Available at the shop — or yet to arrive? (2,5)
I believe the answer is:
in store
'yet to arrive?' is the definition.
(in store can mean yet to happen)
'available at the shop' is the wordplay.
'available' becomes 'in' (I've seen this in other clues).
'at' says to put letters next to each other.
'the shop' becomes 'store' (synonyms).
'in'+'store'='IN-STORE'
'or' is the link.
(Other definitions for in store that I've seen before include "stocked" , "within retail site?" , "coming soon" , "Ready for future use" , "coming in the future" .)