I don't think there is any evidence that they actually need the dollar swap line - the dirham-dollar peg isn't at any risk and they have plenty of money for fiscal flexibility going into the foreseeable future. If you take financial reasons off of the table then it is clear it is just a political play for a bigger seat at the table with the US.

The Saudis did it to Biden in 2023, the UAE sees the opportunity to do it to Trump now.