I just booked K and B fares for TUL-IAH outbound this Thursday and return on Friday. As a Gold I am already inside the 3 day upgrade window and there are multiple F seats showing open on each segment. I still see Medallion Upgrade Requested.

Question - Is it even possible that an upgrade could process within seconds or minutes of booking or do those process in batch on a nightly or periodic basis?

Question 2 - when I'm within the upgrade window is it possible to tell on which flights I would get the upgrade processed immediately?

Yes, it usually processes as soon as ticketing is complete.

And yes, you can see as you hover the "Upgrade Eligibilty". If it's eligible then nothing available. If it says upgrade available then it'll clear at booking.

You can check before your window by doing a dummy booking with a FULL Y fare, although on some routes this will default to a G A P if that's cheaper. Sometimes checking the refundable box helps, but some markets have refundable P fares that can be cheaper than full y, so full Y won't show up when you search on delta.dumb. [I guess they've never heard of travel policies that insist on coach fares.]

It is very common on certain routes for DL to hold several F seats to be sold last minute or to accommodate passengers with IROPS. These seats will not go for upgrades until the gate agents processes them 30 minutes before the flight (if they are still open).

Chances are there are DM and PM who have been in their window for longer than you and are also waiting. Therefore showing higher than you in the upgrade wait list that will be available at check in.
First class seat available does not mean upgrade available. These seats are going for sale and might not be released for up agree until 30min before departure (start of boarding)

Or ever ... Someone can jump in and pay $119 at checkin to upgrade if they give that offer.

I had never noticed that status before. As a Gold, I had to search tons of same day flights and eventually found a couple empty SLC to west coast routes that showed "available" for me instead of just "eligible" or "Not-eligible" or "airport only".

So I guess if I check in and show up 10th on the upg list with 3 seats available, then I can search other flights that same day for the "upg available" status and try to SDC?

It's going to be very unlikely to find any flight with immediate "upgrade available" on day of departure. It would mean that all medallions waiting for an upgrade have already been upgraded, first class seats are still available for upgrade and not for sale.
Most likely at this points, either no seats will be left to upgrade into or there will be wait lists for upgrades until boarding.
Finally, the right fare will have to be available to be able SDC. Not easy either...
One can always try.

As a former DM, now GM I can tell you being a Gold Medallion is a "Kettle with "benefits" medallion status.

I am AA Plat Exec now but booked 2 RTs from MCO/MSP to avoid connections in CLT/PHL. Don't need to miles to qualify for plat/exec so I said, whet the heck lets try DL on a soft route.

FC in the 757 for tomorrows flight was basically empty at the 7 day window. As the DM and PM cleared it got down to 8 opens seats at T-3. Today is T-1 and 7 seats still show as open. Me? Still in Kettle class but was able to snag an E+ seat, which is essentially the "Kettle with benefits" status.

I like DL and achieve 800K+ miles with them. We shall see how the new AA works out for me since I am based in PHL and the US program was magnifico for upgrades at the top tier level.

Curious about your position on the list though. AHev you checked in yet? With most DM/PM already upgraded and still 7 open seats at T-1, your odds must be good, no?

Depends on the route / time. As DM on B fare I've seen 6+ open FC on an RJ at check-in while still not being upgraded. They are holding more and more inventory back at the 7/3/1 day windows, so assuming that because there are 7 open seats 25 hours ahead of time means that all DM/PM have cleared is not a very good assumption.

Yeah, if there are 10 ahead of me on the upg list at checkin on a CRJ 900, that means the PMs haven't been processed yet. There can't be 10 Golds ahead of me on any flight with the level of fares I usually purchase.

Also, just to verify - Does a Y class clear upgrades for any medallion before K or Q for a DM or PM?

Does it really mean that or does it mean that all medallions at my level or higher have been processed. Don't they sometimes hold back on Silvers but would process a GM or PM at booking? Or can that only happen if its inside the PM/GM window but outside the 1 day silver window?

I was citing PepeBorj who is stating that DM and PM have already cleared (see below). I just assume he had other data to support his claims. I'm totally with you you that 7 open seats at T-1 does not mean by itself that all PM and DM have already cleared.

"FC in the 757 for tomorrows flight was basically empty at the 7 day window. As the DM and PM cleared it got down to 8 opens seats at T-3. Today is T-1 and 7 seats still show as open. Me? Still in Kettle class but was able to snag an E+ seat, which is essentially the "Kettle with benefits" status."

If the upgrade is available, it means it's available. So anyone who is next on the list and within their window would clear at the time it becomes available (even silver). For you to see it available on the day of departure, when every medallion is within their window, therefore means everyone has cleared their upgrade (in other words, the wait list is empty).
Unless I'm missing something.