Unless they’re doing some serious DPI (no idea how they would do that on Wireguard traffic other than plain metadata mining), the only ways they can stop traffic is by stopping anything to certain IP spaces, or certain types of traffic through certain ports, or a combination of both. If they have truly blocked the Mullvad IP space, then no this will not work, but OP mentioned using a different app to access them, which lets me assume that it was a problem with the client.
Does the UAE have something similar to China?
Unless they’re doing some serious DPI (no idea how they would do that on Wireguard traffic other than plain metadata mining), the only ways they can stop traffic is by stopping anything to certain IP spaces, or certain types of traffic through certain ports, or a combination of both. If they have truly blocked the Mullvad IP space, then no this will not work, but OP mentioned using a different app to access them, which lets me assume that it was a problem with the client.