Almost no reason. Unless maybe you've been out of the cockpit for a while and not feeling comfortable with jumping back in cold turkey, especially if you flew something non-mobility.

Regional training departments are very accommodating of folks new to 121 and glass jets, especially these days. Any ex-mil (*** with a decent attitude ***) will graduate.

A few months on line at a regional will pretty much remove risk of failure at a major, and also enhance your odds of getting called by your top choice(s).

If you can get a call from your top choice, you should probably just do that and be prepared to suck it up in a training program which may not as forgiving.