beeing pro doesn t matter with ur ability to make a build with good timings.
anyone can do the build part as fast as a pro.

So how well does Tail's DT rush fare with protoss and zerg?

Build-order win vs some Protoss, reasonable opening against others. Vs Zerg depends, if he scouts it with an overlord you can be in trouble. Also spore buff makes it easier to respond, but still powerful as long as you don't get rushed and murdered.

i fell like oracle harass replaced Dt harass

If anything it's going the opposite direction.