Do all UTXO get moved to the newest change address?
If you send 2.5 BTC to one address and 0.5 BTC to another wallet, that is a transaction with two recipients. Change addresses are new addresses in the same wallet.

If the 3BTC UTXO were selected, there would be no reason for the 2BTC UTXO to move. If you want to move all your money to the new wallet, send 2.5BTC to the recipient and the remaining money to your new wallet.

If you want to find out more about the Coinselection Algorithm check out What is the coin selection algorithm?.