I'm assuming by "world level scaling" that it'd be something like Bioware added in SWTOR's later life with the planets - IE, when you enter a zone you are force synced to close enough to its level in a manner similar to when you sync for FATEs?

This seems like a lot of work to change very little. Mob farming, even the large kill counts for certain Hunt spawns, is of little hazard even at level (the ability to farm faster at higher levels is greatly limited by respawn rate, as anyone that's spawned Leucrotta can attest almost immediately upon getting to the Chimeras). Gathering might've become inconvenient in the past with the old gather stealth system, but with Sneak it'll still be a doddle.

The main thing it would seem to affect would be the Hunt, in particular you'd be more likely to need to get help again for old A Ranks. (Whether it would affect trains or S Ranks much is questionable, as although it would limit small groups of hunt "snipers" when it comes to relayed marks, even at-level, these melt rapidly during busy hours: I still remember a Forecaster during prime time that didn't even have a chance to deliver a single Weather Channel, and I'm not sure if it was even 7.2 yet at the time, for that matter)