This has been a problem for me, not sure about everyone else.
I have been attempting to get the last smithing template that I need, which is the Sentry one. But, I have been struggling so much with getting a single Pillager outpost today and yesterday, that's because of how bad the terrain is and it can't generate. I tried 13 Pillager outposts, and no Sentry armor trim. I have generated so many new chunks in my survival world, I had it since 1.19.3 so it's not an old world. You said that it was going to be 25% chance of getting the armor trim, and guess what, I have been getting zero luck and it ended up resulting me in getting a bad headache as I'm typing this.
When I do get a Pillager outpost, it's either on the side of a cliff or on a flat spot of surface (that is what it's supposed to generate on.) I flew past 6 or 10 villages today, flew in all of the possible directions of where it could be, instead it's 5k blocks away in a stupid place. I apologise for turning this into a rant, but it's been a problem for ages.
About the armor trim, consider by upping it to 50% chance, instead of leaving it at 25% chance. It's ridiculous.
The sentry armor trim is located in the loot table properly, bad luck is not a bug.
For change requests, go to feedback.minecraft.net.