Short answer, no.
In fact I do believe most squadrons expect you to continue applying to other units; would it be fair for you to be on hold 1.5+ years for the first applicant to go through the background check, get to UPT, etc etc etc just to tell you "okay he/she made it! Thanks for waiting but you can move on now!"
Sometimes stuff happens where the primary selection can't pass a background check, has a glaring medical issue, or something of that nature that they find out within a few months. When that happens, it's nice to have an alternate to send or (correct me if I'm wrong) the unit just loses that slot for that year. So everybody wins, but keep applying.