So, this has now happened twice where I'm going between 55 and 65 mph and the engine will stall. I don't recall specifically what led this but I think that I likely tapped the brakes. Both times there was plenty of fuel, the most recent time I had just filled up.

They happened a few months apart and I put almost 1,200 miles on the bike between incidents. The bike fired back up fine both times and ran fine the rest of the day. I'm wondering if I'm starting to see the petcock fail; should I be proactive and put on the raptor? Or is this just some weird fluke and I probably just did something wrong? Both?

Bike is stock, 2009 and has just under 8,300 miles on it.

You might also check and lube your sidestand.
If it doesn't return all the way, or gets bumped, it will engage the sidestand cut-out and kill the engine.

Go for the Raptor, new fuel line, because then at least you'll know that the fuel supply is okay, plus, if you need to take the tank off the bike, it'll make life easier. The genuine part is reasonably cheap, too.