Confirmed on his Facebook page yesterday -

Absolutely gutted to be out of Isle of Man TT Races 2023, I have done everything over the last two weeks to be physically fit after my crash in the Superstock race atThe North West 200 but it wasn’t meant to be for my bones to heal in time.

I wasn’t going to be 100% fit and with that I wouldn’t achieved the results I knew I was capable off, I would have been more frustrated riding round not fit to a possible 15th place in pain to then jeopardise my career further down the line when I knew where I could have been. I’m only 24 years old I have plenty of time on my side as hard as it is to take right now.
I have put everything into this year as always, from 05:30am gym sessions before work to millions of laps on board laps and laps in the car over the winter, but I have come back from a lot worse before and will use this just like I did last time to come back bigger and stronger for the second half of the season into TT 2024.
I also have to be careful because if I went out there and I wasn’t 100% fit I know if my Mum was here, I wouldn’t have had a chance and if I did she’d of give me a massive telling off!
I would like to say a big thank you to Havier for the advice and support in the decision & the whole Honda Racing UKteam for everything and support up until this point of the season and the chance, all my sponsors supports and family for the support. We will be back!
See you all round the Grandstand where I will be supporting John & the Honda Team.

surely it was never going to be anything other than withdrawl

The right decision - I've always hated seeing injured guys getting onto bikes to race (all that 'I cut off the cast' heroics we used to see) - the stakes are just too high IMO.