most of the f2p offerings are games with energy systems limit play. And in those cases you simply have unlimited energy, or the entire energy system is removed. For other types you have ever jigsaw puzzle etc that was ever available for the game. Sometimes you need to go in and claim the dlc and it'll then be active for you for as long as you are subbed (and as long as the game in question is part of the program) Usually the games that have heavy p2w and FoMo built into the core gameplay loop and mechanics don't show up. I assume it's because it would be way too much work to make the game fun to play and that they don't want to give people a way to avoid the monetization.

2 examples I can remember easily: The Battle for Polytopia has every single faction unlocked from the start. Titan Quest is based on the earlier version that only had the first expansion, so the 2 more recent expansions are for sale in the ingame menu, but since you have play pass you just hit "download" on them and get them.

I wouldn't expect to see a lot of clash of clans or raid shadow legends -types of game there, because "real money" is an important and significant resource in those games.

The amount of effort spent to convert the game to play pass varies, but in almost every game it's not a detractor.