This will never happen, because Roku actually makes a significant amount of money from various streaming providers for locking those buttons onto their services. This is also why the particular four buttons included change over time. I guess they sign contracts for a specific span of time, or maybe covering X number of remotes manufactured.
I never use the buttons, even for services we do subscribe to, but don't really mind their being there, considering it helps keep Roku in business, and (in a way) helps subsidize the device costs.
It'd be nice to have more than just two programmable buttons, though (I thinks these "1" and "2" are present only on voice-capable remotes).