Well the requirements are not that strict, nor can they be verified. Maybe not your average attention-seeker will do it, but what is the average attention-seeker? Is op average, below or above? It leaves us at assumption and that's the problem with it. No one is making an assumption about others, only pointing out the very reasonable problems that creating fake accounts and personalities cause around something like ctb. Consider any responses you took the time to write and then pause and wonder how messed up it is if you were writing sincerely to a fake personality. We can never know of course as u said. But it's a good reminder to say out loud to any fake posts/posters that it's manipulative and fucked up and not welcome here.
Below attention-seeker? Above attention-seeker? What does that even mean, lol? Average in this case would refer to the majority rather than the minority. There is no above or below...
No one is making an assumption about others
There are a lot attention seekers here, more than a few years ago.
^This literally implies that they have made assumptions about others before. You wouldn't make a claim like this unless you were assuming that other users on here are just attention-seekers.
They are making a huge claim, which is that there has been an increase in attention-seekers on this site, but based on what? Unless if you have good evidence to support this, which they likely don't, then you are just making assumptions at the end of the day. They aren't pointing out a very reasonable problem because there isn't really any good evidence showing that this is a growing problem on here in the first place.
Along with that, an interesting thing to note is that attention-seeking behaviours surrounding suicidal ideation doesn't necessarily mean that the person isn't suicidal. They may just be using their actual issues with suicidal thoughts and urges to gain more attention as a last cry for help or understanding before acting on those thoughts. It's already well-known that it isn't uncommon for suicidal people to mention their suicidal thoughts to others before attempting, especially in the manner that the OP described.
Either way, this person is making a huge claim that they likely don't have much proof to back up and it's harmful. This type of rhetoric already has a long history of being used to invalidate the people's issues with wanting to ctb, so I don't think that anybody should be making such huge assumptions like this on here. Let's just assume that people on here are being honest unless proven otherwise.