Not riding in it is one thing, riding in a Championship match on the same night quite another.
The Championship fixtures were set out well in advance of any Premiership planning (which would presumably include Belle Vue's dates) so we cannot blame the league that was organised enough to publish an early schedule.
Maybe the winner in August will be the wild card for the 2027 British GP? Making it slightly more appealing to some riders?
If the Championship schedule was maintained, and the meetings at Berwick, Plymouth and Workington (featuring Oxford, Edinburgh and Poole) went ahead, there wouldn't be sixteen British riders available to turn out at Belle Vue!
Thus, the three Championship matches will have to be postponed -- which is a pity, given the clubs and supporters involved will have been issuing fixture listings and planning travel.
Not a good look for the BSPA this time, seemingly running roughshod over the lower(?) league's more-efficient planning. Their capacity for both having and eating cake remains unrivalled.