As a Horizons owner and Beta Backer, not only do I not have a problem with this, I have in fact said in the past this has been needed to be done. the problem with having Horizons as a system was that the dev team was almost duplicating their efforts by having to develop any given mechanic with two design philosophies in mind, one WITH Horizons and one WITHOUT. An example of this is the fact that synthesis material was for a while, only on planetary surfaces and subsequently synthesis was only available to Horizons' owners. Which meant in a fight between a Horizon's cmdr and a Non Horizon's cmdr, one could reload in the middle of a fight, the other cannot. Now the fix for this at the time was add synth materials to asteroid belts and mining rings, which was good. It also meant explorers with dead srvs could synth, life support should they need to.
More over other gameplay mandates for "core gameplay" had to be limited in scope and planets basically were left out because again, planets are not "core" to the game.
By merging Horizons, planetary surfaces of other horizons limited features can be included in the core gameplay loops and functions. Developed more as a holistic scope. My hope is that Fdev isn't going to simply repeat this mistake with Oddysey.
My hope is that they do repeat that "mistake" because if they don't, then it will mean that Odyssey is entirely disconnected from the rest of the game. In order to avoid the "mistake" - they'd have to make it so you can't earn anything interesting that translates into the space ship flying part of the game, and vice versa. That would be sad.