It's not necessarily about who was cut (Hannah has mixed opinions on here), it's the matter of how and why she was cut, and how they've made up a story to cover their backs.
There are two main issues here. Firstly, TC really shouldn't have taken place in any capacity this year. People should only be leaving home if it is necessary. If Covid isn't stressing you out, then you must be extremely privileged. (I don't mean you in particular, I mean in general). The problem is that people (especially the US) aren't taking it seriously enough (large gatherings still taking place, no masks in sight). In the UK, we're on lockdown 3, numbers are still rising. Half the population are adhering to the rules, the other half are simply doing what they want especially over Christmas/New Year.
Secondly, Hannah and the vets/TCCs were told that the bubble was secure, which probably eased her anxiety initally. She loves being on the team and wanted to continue so under the impression that all precautions were being taken. She's said she found escapism in dancing in her basement but it wasn't quite the same. On turning up to the 'bubble', it was clear that it wasn't as secure as they had been told. She voiced her concerns and got blacklisted and then cut for that. They have a responsibility as an organisation to make sure that they were taking all Covid precautions.
They know of her medical history as she's been vocal about her anxiety/depression on the show before. That doesn't mean she can't go anywhere or do anything. She has been a great ambassador and stellar performer for 2 years now yet now she's no longer capable? Kelli even said her heart doesn't seem in it and she's less engaging. Probably because she doesn't feel safe, which she shared her feelings about, and now TPTB have made up some story to make her seem disinterested. Having watched the episodes, her dancing doesn't seem as powerful as before but she's still head and shoulders above a lot of the women there.