Hi all. Newbie here, haven't flown AA for quite some time.

In a nutshell, I'm coming home (BOS) from a trip to Turks and Caicos (PLS) in April. I've booked one-way going down to the Caribbean, but the outbound flights are outrageously pricey (spring break, uuugh, wasn't my idea...). I have booked a fully-refundable (class Y) direct flight BOS-PLS, but it's $900/person (there are 3 of us) and it's killing me! I was thinking of booking a flight the day after we got home to go to Philly to see relatives we haven't seen in forever. However, I found this flight combo here, which is actually $300 less per person, which is kind of blowing my mind.

PLS-BOS 1:20PM-4:58pm (same flight i'm booked on now)
then overnight layover in Boston (perfect, so I can drop my vacation bags and refresh)
BOS-PHL 8:30AM-10AM

What's the catch here? I NEED that overnight in Boston (with my bags) to get myself together before going back out to PHL. Actually, if it the layover got shortened I'd be ok too, as long as I'd have access to my bag (it's a quick trip home). What are the chances that AA screws me over and says heck, let's just re-route you straight to PHL! Or am I overthinking this and just cancel the original and go for it (or maybe AA would be so kind as to just switch it and refund me the difference?). Never been in this scenario before

Thanks much!