Either would be fine - especially in the case you mention (Yoshino cherry in zone 7).

Pruning in spring (just before bud break) has a couple of advantages for many woody plants. Marginally hardy types of trees may be less likely to have dieback around pruning sites due to cold damage, and early spring pruning minimizes the time for wound covering (because the tree isn't going to do much of that during winter months).

There are some tree/shrub species, who tend to "bleed" excessively, that bleed less if pruned in late fall/early winter (after dormancy) rather than in spring or summer.

most peeps do NOT prune prior to flower... just to see the flowers ... ergo would default to after flower.. or fall ...

i tend to prune everything.. when they piss me off and i go get the saw ...

if you want pruning guidance.. give us a pic ... know all about branch collars and that stuff????

ken