I seem to recall there's a website where I can find info on aircraft swaps..

I flew DL145 AMS-SEA on the 7th and realized on the way to the airport they had swapped from A339 to the A333. Then I looked further and it seems that when I booked this trip all the flights were A339 but now I noticed on FR24 most, if not all, of them are running the A333. My return on April 30th also appears downgraded to A333.

Related question- if I fill out the comment form to file a first world complaint about losing the Suites, whether they'll throw some miles my way? lol..