In a typical year, some roads (such as Tioga Rd) r still closed

in Yosemite. This year is warmer than usual but you can expect some roads to be still closed. Check Yosemite NP website for up to date road conditions. I personally think spring is a better time to visit Yosemite than say summer, as it is way too hot and crowded in the Valley in summer and many waterfalls tend to dry up.
You have to check DOT hotline or website for real time info on the day of your travel. No one knows if chains are required this far in advance.