I had a very similar question today. So if the HR/VO2 max intensity stays the same, maybe no issue in terms of getting what you need out of the indoor ride. In which case I would definitely rely on this to get thorough some harder intervals!
Does that mean these V02 max intervals are also the best workouts to intentionally target doing out of the saddle work? (vs. maybe try to avoid that on SS/threshold to build the steady endurance?) At some point I would think it must be good to also build some strength out of saddle on the trainer as well - for me, I sometimes notice the front top of my quads get a bit twitchy if I jump up for extra power when already well into a ride. When I was first riding, I was a lot faster to hop up on hills till reading that it’s less preferable for efficiency.