I would mildly chuckle and not expect any response from the CEO about it. I would mostly expect there to be a new twitter profile with an extra underscore in it, after a small appeals process.
A twitter account getting suspended after growing doesn't mean anything. It can just as easily be some random automated system flagging it, or a competitor or disgruntled customer.
I also wouldn't care if the CEO was buying followers and not telling anyone. Who cares. All this stuff is very relative. The investors are probably using laundering oligarch money in one of the feeder funds, and the business' "organic" customers are probably just other portfolio companies of the investor, juicing the revenues of other companies using the exact same capital.
You get paid either way. You are getting paid right?
If you are sensitive enough and privileged enough to think any of this matters and that you need to "choose" a company that has every single thing organic, interesting, popular, has perfect managers, perfect co-workers, and a perfect work-life balance, why are you even working?