"So again Tweetbot isn’t going anywhere, if you are worried about us running out of space well the solution is quite simple buy or gift Tweetbot for iPhone and Tweetbot for iPad now."
While it is unlikely to happen (as calmly put by Paul), the sooner you use Tweetbot, the more likely you can secure a spot in Tweetbot's user allowance.
And as Paul stated about user tokens:
"User tokens are shared, so if you have a single account on both Tweetbot for iPad and Tweetbot for iPhone that’s only a single token."
So if you were ever on the fence about using Tweetbot (and you haven't purchased any version of the client), the smartest thing you can do right now is secure your spot by purchasing either the iPhone or the iPad version.