I think that is Ed Laivo from Dave Wilson nursery. He and another rep named Tom Spellman have a series of videos on youtube showing how to keep these trees small. Look up backyard orchard culture on youtube and look for the videos from dave Wilson nursery.

With sweet cherry , it starts at rootstock. what rootstocks are your trees on. Where are you located. In colder zone, zone 6 and lower, it is suggested to avoid pruning cherry in winter/ cold temp or in wet weather to avoid disease like canker.

even dwarf rootstock, it can be 12-15 ft if not pruned.