it interferes with the ability to open drawers
It's funny, but I tried looking around the old Material Design guidelines and I haven't come across any mention of swiping to open a drawer. I know it was on Android Developers, but it appears that from the point of view of the design team, it wasn't really "officially" recommended?
Regardless, Discord, IMO, offers a better implementation for side sheets, as the metaphor isn't that you drag something from beyond the screen into view, you just drag the view itself to the side and that reveals the side sheet. And it works in the middle of the screen so it doesn't interfere with the system gestures
Yesn't. Material Design 1 and 2 guidelines have a bunch of sections regarding interaction, way more than M3 (although M3 guidelines aren't "finished" yet), but they lack a section regarding that gesture in particular.
Like, M1 guidelines mention swiping on content to swap tabs, heck, you can even find the same on the current Material Design 3 guidelines
I think it was a conscious design decision from the Material Design team to not use that gesture in particular? Because it isn't due to conflict with other components, in the tab guidelines they call attention to be careful when the content itself is swipeable.
I mean, you already can't have certain gestures with other gestures. Like you can't (or shouldn't) have swipe on a card to upvote at the same time you have swipe content to change tabs. I'd argue this restriction is better for the user because with discord's implementation it is very clear what the trigger area is, because the entire view is the trigger area.