Is that really the most likely? I'd suggest it's much more likely that they tripped some automated spam protection or a moderator thought they looked suspiciou

Is that really the most likely? I'd suggest it's much more likely that they tripped some automated spam protection or a moderator thought they looked suspicious, than there's a conspiracy against the company by a competitor. That conspiracy would be of a high reputational risk to Facebook and the competitor, and would have a paper-trail in contracts that guarantee Facebook that ad revenue for the deplatforming. It seems highly unlikely to me, as much as I believe Facebook to have poor moral standing.