The reason that Scourge has no interactions with Revan in Maelstrom Prison is, that on the SWToR timeline Maelstorm Prison's events happens way before the Jedi Knight meeting Scourge. Thus, no interaction, because it would be a paradoxon / non-canon.
That is not entirely correct. Certain Flashpoints do have reactions going on if you're soloing it. In Maelstrom Prison, if you make it to Kilran all by yourself, he will comment on it, saying something along the lines of it stretching credulity that a single operative caused all that trouble in the Maelstrom Prison. Likewise, in False Emperor, if you have HK-51 with you and you win the role for "Hello, HK-47", HK-51 will make a snarky remark about how outdated HK-47 is. That even happened to me when I was in a group of four and HK-51 was merely the companion I had on standby.
This reaction of Kilran, on the other hand, is possible, because the canon doesn't state, if Maelstorm Prison was done with a Strike team of 4 players or one singlehandely.
But intererstingly, the reactivation of HK-51 should be after defeating HK-47, since 47 has a component for 51. So we can say, we have anon-canon easter egg here.