Fun fact: Alabama, Mississippi, etc were once The Old Southwest for similar reasons.

Is this actually a new trend or is it just infinitely easier to notice because everything is online? Actual question because I really don't know the answer but I bet it's not not a factor.

In 1992, you couldn't randomly click through a dozen job boards and anonymously see what's going on in a matter of seconds. You'd have to spend a decent chunk of time actively seeking this info: calling specific places to ask, going to a business in person, telling other people that you want to know about job openings. There were want ads in the paper but they were nowhere near as robust as what you get by simply typing "veterinarian jobs" into Google, and newspapers were geographically specific. You wouldn't see openings from all over the country like you can with online job boards now, either.