Question about bots/accounts in regards to crypto subreddits

I follow some coins and the bigger crypto currency subreddits. I usually like to see the comments and view the profiles. I try to see what other coins/projects they are interested in or other interests.

However, I have noticed that they have accounts that go back years and will have made comments/posts (that have nothing to do with crypto) up until about 4 months ago and then suddenly it will jump to a month ago or even a few days ago then they have been routinely (almost frantically) posting and commenting on cryptocurrency subreddits. They don't make comments or post on their other interest anymore. Could their accounts have been hacked? Or turned into bots? To shill/hype projects. It would make sense to steal/hack an account that's older to maybe make their comments seem legitimate. Please let me know what you think... Thanks