If that is the case, then it's just flawed ruling. It goes both ways, you said it yourself, takes the dev 10 mins to write something on Patreon, regardless if the game is being developed or not. If we're assuming a dev is lying on discord, why exactly are we taking any pieced together Patreon post at face value? We either belive the dev or we don't, I don't see logic in disregarding one method of communication over another. Just look at how long Icstor was able to avoid an Abandoned tag.
Sure, not posting progress reports for that long is concerning, and maybe this game might end up Abandoned. But to me, the actual time since the last release should bear FAR more weight than Patreon posts. There are games in here that haven't updated in over 2 years that aren't tagged as Abandoned, while this one gets tagged after 6 months...
I never said that we're assuming the dev is lieing, and I see a few things wrong with your logic there, first, this site manages a lot of games, so asking for them to refer to all possible ways of communication the dev might have is just not an option, they refer to the most important one, where the billing happens, second, connected to the previous one, Discord is totally optional, the only place where a dev is 100% sure to reach all his followers, is the billing site (at least the ones that pay which are the only ones that matter really), so that's where everyone would expect to see the last news on the game.
The time between updates is in fact more important, but if you were a paid subscriber, and only looked at updates, by the time you noticed the game was abandoned, you'd have paid god knows how many months while the dev wasn't even working on the game anymore, so the communication requirement is just a way to preemptively notice that something might be wrong with the development, and you might start thinking about if the dev diserves that sub, or another dev that cares more should have it.
This is not about knowing if the game is really abandoned or not, or if the dev is lieing or not (which is impossible to know really), it's about the fact that when a dev stops posting on Patreon, you can only expect it to go worse as time goes, for me, the Abandoned tag doesn't really mean the game is abandoned, it means the dev is not turstworthy enough to follow a schedule, and that doesn't exactly makes me want to pay him, all the work he does doesn't matter to me, if he can't post updates on his work.
So, when you see abandoned, take it more as a warning like: "hey, this dev didn't comunicate in the official site for long, be advised that he might have abandoned the game, or maybe he doesn't take this seriously".
As for games that don't have the abandoned tag, but should, that's probably because no one is following that game closely enough to notice, I'd imagine the mods don't really check all games, most of those are people reporting to ask for the abandoned tag, so if a game is past 2 years with no updates, or posts, it's either because no one cares and no one noticed, or because it has some special condition, some people for example, though Bare Witness was abandoned because there are no updates in a very long time, but the devs have said that it's taking longer, because they want the next update to be the last, and will be completed after that one.
Sorry, this was way too long, don't even know if I repeated myself anymore... At least I hope my point was stated fully and it's understandable, if you want something else, I'd rather continue on PM, I think that continueing this on this thread is pointless, snce it's not really about the game anymore xD.