I check #Twitter daily, but have not posted there in over a month at least. This morning I found myself logged out for no obvious reason. No problem getting back in, but still perhaps worth noting.
I'm pretty sure that what you experienced is expected behaviour.
You need to login every 30 days, otherwise, at some point, your twitter account can be killed off or taken over. At least, that is my understanding.
There are people here on Mastodon, that have deleted all of their posts on twitter, but still periodically login to twitter to prevent issues.
Right. As I said, I am not sure either.
But, there have been many that were wary.
And one reason that Twitter would change the behaviour, is to HODL.