Castlevania Advance Collection leaked courtesy of an Australian rating
PC release not confirmed.
In 2019, Konami released the Castlevania Anniversary Collection, collecting eight of the classic Castlevania games and making them available again, including on PC. It didn't include all of the fan favorites, however, like Rondo of Blood or its sequel Symphony of the Night. Word of a new collection, not yet announced by Konami, has snuck out via the Australian Classification Board. On June 18, the Castlevania Advance Collection was rated M for "fantasy violence" in Australia.
The name suggests this will be a bundle containing the Castlevania games released on GameBoy Advance: 2001's Circle of the Moon, 2002's Harmony of Dissonance, and 2003's Aria of Sorrow. So no, Symphony of the Night seems likely to be left out again. Sorry.
The rating for the Castlevania Advance Collection describes it as "Multi Platform", so a PC release is not yet confirmed, but since the Castlevania Anniversary Collection did make it to Steam it's a fair assumption this will too.
Meanwhile, Netflix is working on a brand new Castlevania series now that the popular animated show has wrapped up its fourth season.