This is not legal advice. It is not intended to create an attorney-client relationship. This attorney is licensed in PA and NJ.
Your question - no the Executor/Trustee cannot "change" what the beneficiaries are to receive. The document controls that. Keep in mind that there are often estate expenses and taxes which reduce the amount in the estate. Keep in mind that a person (decedent) is in no way obligated to tell you what you are to receive and they are able to change that up until death, assuming they have the capacity to do so. As a beneficiary you are entitled in some form to a copy of the document (will/trust, both) and an accounting of what went in and out of the estate. Many executors/trustees ask that the beneficiaries sign a "release and refunding bond" or similar such document which would indicate that you either reviewed an accounting or had a chance to review it but waived it. I believe Florida usually uses court accountings but this would be avoided with a living trust (you say living "will" but I think you mean living trust).
This is not legal advice nor intended to create an attorney-client relationship.
A trustee cannot change and you would have the right to see it, so yes contact the probate a ttorney, but bear in mind what youu wer told is not controling, the instruemnt is and it is far more likely that Granny changed her mind, which is he rright, ten that aunt changed it.
Sonya Mittelman is aNew York attorney and hence her answers ar ebased on New Yotrk Law. Please seek advice from acompetant attorney in youru own state