Running one iPad (3rd gen) here and one Android tablet. The iPad has not been able to get past mojang logo since 1.13.0, the Android tablet had been mostly fine save a few small glitches.
I can see that the latest 1.13.1 update has just reached the Android tablet. No idea where the iPad is concerned however, as it still can't get past logo screen.
There are a lot of mentions that the problem could be to do with a Microsoft account. This is definitely not the case. We do not use either a Microsoft account or an Xbox live account on the iPad which is currently experiencing the problem. We just use the app without logging into any additional accounts. If I look at the Microsoft link Urielsalis provided earlier my iPad is not listed as a device.