It's not like he's moving to the EU which I agree would possibly arguably make him seem like a hypocrit. He's moving to a non-EU country tho, so.... ?
January 22, 2019 - Dyson announces move to Singapore. [1]
After such strong support for Brexit, it is not a good look.
[0] https://ec.europa.eu/trade/policy/countries-and-regions/coun...
[1] https://www.theguardian.com/technology/2019/jan/22/dyson-to-...
I am not sure this mattered in the decision much.