The answer to this question is most likely, 'I don't know'. But;

was the first weekend of June for the Shefford Tour a confirmed date, or just an idea?

The lads here are ahead of us in the planning stages of theirs (which is embarrassing) and that's one of the weekends they are looking at (the first three weekends of June are the three they are looking at), so therefore if it clashes, I need to tell them I can't make it.