I am going to buy a new smart tv and I also want to buy the new Roku remote. The website only lists any compatible tvs/streaming devices that are already installed in my home. How can I know if it will work with a specific future tv purchase?
It depends on what you mean by "work with any smart tv". The remote should be able to control the power and volume/mute of any TV you purchase, but if it's not a Roku TV, that's all it will control. If it is a Roku TV, the Pro 2 remote will be able to control everything. It's unlikely that there will ever be a Roku TV that the Pro 2 can't control.
It depends on what you mean by "work with any smart tv". The remote should be able to control the power and volume/mute of any TV you purchase, but if it's not a Roku TV, that's all it will control. If it is a Roku TV, the Pro 2 remote will be able to control everything. It's unlikely that there will ever be a Roku TV that the Pro 2 can't control.