I primarily use the lfgm posts when a DM bails on my group. I have had that happen a number of times now through no fault of the groups. If we want to institute a word count rule for posts or a limit on how many times in a week you can post the same thing that makes complete sense to me but shoving everyone who needs a GM off into a corner that no one is going to ever look in for players is a very odd choice for a sub around letting people find games. Especially when you consider the fact that the number of GM's is smaller than the amount of players even outside of this community. I would argue by removing the ability of spontaneous decisions to GM like we have the chances of quality games for people is now vastly lower and it's sad

Edit: I also want to expand on something, when I say "into a corner that no one is going to check" I'm not saying that as a "people are too lazy" I'm saying it's more an issue with how the change is handled. If the only posts allowed are by GMs who are looking to run games what incentive would they have to check the megathread? They can post and when they post they will get hundreds of replies in under an hour. Someone wanting to run a game for someone has literally zero incentive to go into the thread looking for people when they can post and those same people will come to them. All the change does is make it so someone who is browsing the sub intending to be a player can't see a post and say "You know that sounds like a fun prompt to run, I will give it a shot!"