Wow, just look at all those applicants with tons of posts and no merits whatsoever. I'd been wondering if bounties were still a thing here (and yet was too lazy to check if the section for them still existed), so I guess that answers my question.
The way I see it we should do what is right regardless that account is a throwaway one or not, but I already see you support the flag.
Normally I'd say it's a waste of time creating a flag or even tagging a throwaway account, but in this case I agree with you. Who knows if this one would pop up again maybe a year from now--and if it did and there wasn't a warning on it, well, that's an invitation for further shenanigans. Feels like late 2017, doesn't it?