Proper emulation is cpu intensive. From what I understand the ps2 "Emulator" is just PCSX2 using the hardware plugins. That has glitches still and all post processing effects don't really work on it, so you have to test the games individually. The software plugin needs a pretty good CPU. Not sure if the default jaguar can handle it.Maybe they invested in a new internal emulator.
The problem though is that it'd be close. Pro's CPU isn't that much stronger and on top of this, the competition is doing much harder BC. Pro exclusive PS2 BC would be met with "oh but couldn't you do better Sony?"