I have been with React for 4 years now. Link state can be driven through React if you are testing some state or URL (active URL). But hover should never be React driven. I can not fathom why anyone would do that.
The first legit reason I can think of is if you have a particularly complex UI with fixed/absolute/sticky positioning and you need tooltips. In this case, CSS gets in the way and you need to render the tooltip through a tooltip and so need to set the position using JS on hover.
