My reading is:
New averages on 1 June see reserves unchanged [Poole have no more matches before 23rd cut-off]
27 May Coops rides his 6th match
3 June Coops gets average and Newman (5.03 vs Bowes 5.05) drops to reserve with Rushen moving up.
23 June average cut-off. Averages updated but with only one match since 23rd May there will be little change. However Newman, Bowes [if still in the team] and Cairns will be sufficiently close any two of them could be reserve for July.