Again I think it depends on the horse and the owner. Ours, I plan to keep all the days of their lives. I'm not a horse trainer I'm a horse owner. Go ahead and call them pets, that may be what they are. I do believe in letting them just be horses for the first 2 years. Nothing beyond halter breaking so they can be doctored, feet done and handled safely.
I don't allow disrespect from a horse, but I do want the trust that a long term relationship will build. I think it comes down to, you do what works in your world and with your horse. There is no one way to do something, just as there is no one personallity of horse or human. What a boring world it would be it that was true
I also live in a place where a horse can be worked well outdoors year round. If your someplace where winters are a time off, your time line may be different.
"Until one has loved an animal, part of one's soul remains unawakened..."
- Anatole France