I've done hypo in DT without any issue. Even had one large hermit crab that somehow survived that and copper without any issue at all. Seems unaffected. This is NOT normal and you should remove all inverts.
I had no cycle. I also can tell you skimmers will need adjustment as you adjust the salt content.
I should've asked this question before on my last hypo. Will the skimmer need to be tuned down or up with less salt? From what I saw in my last hypo. I had to turn it up in order to get it to skim anything. And by the time I realized this my nitrates were on the way up