It's not surprising to me at all, and these jokers probably need to be banned.  I've seen the exact same thing in the past in the altcoin ANN threads, where a given thread keeps getting bumped with idiotic "great project, good luck" posts by newbies.  It's obvious to me that they're alt accounts, and the last time I visited that section I reported a whole bunch of these posts.  That's what I recommend you do, and perhaps mprep will ban those accounts you listed.

This is all a common tactic among those who are promoting ICOs.  They don't care about bitcointalk at all.  They just want their thread on top so everyone can see it.