I'm pretty sure the old episodes (1-206) won't be in HD.
Yep, they won't look any better than the Funi DVDs. 207+ will be where these Crunchyroll episodes will really shine in HD, better than most of the online raws. So pretty much everything from the Davy Back fight to the end of Fishman island will look outstanding. There are blu-rays for Punk Hazard and beyond, so Crunchyroll won't deliver top-tier quality in comparison to those since the blu-rays will almost certainly have superior bitrates.
A little curious is they're able to do the Toriko (and DBZ) crossover episodes now. While they're pretty much disposable, they do technically qualify as official episodes.