Rarbg actually let me know of new releases quicker than any official site. It’s the thing I miss the most about it. Hoping there’s something similar.
There is a group trying to copy it at therarbg.com. Standards are not as high as rarbg as it appears and content is still being imported, but the interface is familiar.
You can also try bitsearch.to, which is just a general torrent indexer for torrents.
Neither is as complete as rarbg was. Ideally therarbg and others will come to fill its place.
This is only a half-answer, but you can use one of the Pre DB sites to see scene releases. It won’t really help with P2P releases. Scene is almost always first (nature of the beast), with P2P releases of the same showing up a day or two later.
rlsbb.cc, hdencode.org…they are ddl sites but you only look for new releases so…
This page on Torrent Galaxy has become my RARBG replacement. Shows new releases without having to sort through all the garbage.