Agree. If anyone should be investigated, it's Izzard. It's incredibly offensive of him to appropriate the Holocaust in this way and to suggest that he would have been targeted by the Nazis, when trans people were most definitely not targeted by the Nazis, not least because the concept barely existed at the time.
It reminds me of what happened to Helen Mary Jones of Plaid, who retweeted a tweet by Rosa Freeman, which criticised Jo Maugham for offensively making an analogy between what was happening to trans people and what happened in Nazi Germany. Bear in mind that Rosa Freeman is Jewish, so had the right to take umbrage at Maugham's analogy. Yet it was Jones who was forced by her party's leadership to apologise.
These people who weaponise the Holocaust for their own ends disgust me.