HF22.2 was controversial and I wrote posts about what I thought about it. There were two possible routes:

• Justin Sun was planning to take-over Steem anyway and the witnesses therefore were right to temporarily (!) limit some of the actions he could take until we could talk to him. In that case current actions taken by him prove they were right and the measures should maybe even have been more decisive.
• Justin Sun is innocent, was really planning to do 'everything good' we wanted, and never planned to take over Steem in order to grow 'his' Tron. In that case, the decision of the witnesses is the sole reason the current SF22.5 is happening as he felt he had to protect himself.

There's a lot of evidence suggesting he was planning something 'hostile' all along. Amongst others: 1) screenshots with announcements that Steem would be made worthless by adding a Steem token on Tron and adding that one to the exchanges instead of our own $STEEM, all these announcements have been removed from the twitter and medium pages, but the screenshots still exist, 2) him ignoring the pressing questions that he said he would give 'the highest priority' during the AMA, these were questions that would have been able to reassure us, but he chose to purposely ignore them, 3) him ignoring many requests to talk to him in calls - witnesses did have ideas on how we could keep the status quo without doing a soft fork, but he chose to ignore these invitations, 4) his recent voting in of Tron Super Representatives, showing he is willing to use his money to get a blockchain to do what he wants, instead of trusting the consensus.

So, to answer your question:

But if you call this "hostile takeover" by justinsun, what was HF22.2?

HF22.2 was a protective, temporary (!) and reversible (!) action taken by democratically chosen (!) witnesses to keep the status quo on Steem and find out if Sun would use his stake as it was meant/promised in the past.

I hope I answered your question.