If there were any available at OLCI then presumably, yes.

But in my (limited) experience, the best you can hope for as an FB Platinum is to be put on the "upgrade list" for a day-of-departure move up to the Comfort+ cabin once all Delta elites have been dealt with. On my last DL flight, I was second-to-last on the list (33 out of 34 or something like that) - but for most of the time (you can check the upgrade list through the Delta app in the days prior) I was dead last, so presumably an FB Gold/Silver or some other equivalent status level in another programme, requested to be put on the waitlist after I did. Naïvely, in the days leading up to check-in, I thought my odds were pretty good because there were only about 6 or 7 people on the upgrade list. All that changed on the actual day of departure.

In the end, the flight went out with the Comfort+ section absolutely rammed full, and the rest of us "plebs" each had a row of 3 seats to ourselves to stretch out in in the rows just behind Comfort+.

So...I really would not expect to get any "upgrades" on the strength of Flying Blue status, because Delta status holders of all stripes jump ahead of you on the list - the same for Aeromexico status holders, I believe - and unless you're travelling on a route or flight for which the flight is practically empty, you're more than likely to be pre-empted by a late surge of Delta elites who then swamp the Comfort+ cabin.

You might be better off picking a row further back where you might have a seat free beside you.