Portability wise it can’t be beaten and personally I’d prefer the size for reading texts on, but it may not be the best Apple Pencil experience on that screen size.
If you are buying from Apple, you could try it and then return it for the Air or the standard iPad should the Apple Pencil experience prove too much of a compromise.
If the OP favours the Mini for its size and doesn’t mind the pencil experience on the smaller screen, then it doesn’t make sense to wait. The Mini was only updated in March of this year, though the altering of the storage sizes in 2017 has reduced the average time between updates and has led to the buyers’ guide giving it a neutral status.
he said he is thinking about the mini not that is sure for it..
I think the mini is a dying thing...i think with a proper update for the base ipad....10.2" can be a big deal if he dont want the 11" iPP