So a few days ago I booked what I considered a "deal":
BOS - SJD via LAX in D1 (I know it's not "real" Delta one per se) for 49,000something SkyPesos (cash rate was $690). For 6/1/24 travel.
I figured I'd try to setup a google flight alert for the cash price or something in case it dropped.
Google only showed 2 flights BOS-SJD on the dates in question. None of which were via LAX.
So I went to Delta.com and searched. More flights showed up, but NOTHING via LAX and NOTHING in D1 (and the lowest price was like $1300-1400 cash).
My itinerary still shows the trip is "valid"
Expert Flyer shows the individual flight segments are valid.
If I search Delta.com for just the BOS-LAX and then the LAX-SJD, they are there (flight 479 and 1884).
So now I'm a bit worried that DL has somehow scrubbed/cancelled that particular route/flight (I guess it wouldn't be the end of the world). AND I know that there will be schedule changes for something booked that far in advance.

Last time something like this happened to me, Delta had actually cancelled SERVICE to CZM (like you can't fly there period) as it's apparently a "seasonal/regular" thing they do (but yet they still sold the flight, but whatever) and I ended up having to re-route through CUN (added another 4 hours travel time because we had to ferry over and then taxi up to CUN).

I tried "multi-city" in case it was some odd booking thing, but delta.com wouldn't let me. I see something on AA forum about BOS-LAX flights going "poof" as well, so possibly this is a "seasonal" adjustment that's "normal"?