I don't know that this is news, exactly.
Russia has had a treaty of some sort with Syria since the '70s.
I think the fact that Russian regulars are operating away from their bases for the first time is indicative of how much damage the Syrian Army has taken.

This is nothing new. Russia and Syria have had close ties for decades. Of course, Americans have no clue about any of these dynamics because they have a short attention span. Media is just presenting it as something "new" because Orange Man Bad.