Well, the thought is it doesn't differ people who participate signature campaigns. The difference is you could only hold it as investment once received or exchange to fiat on Dubai, and who would think bitcoin price will collapse, its possible but it will not happen overnight unlike any other altcoins.
If Dubai starts paying its citizens in Bitcoin then Bitcoin won't lose value but gain more value overtime. The reason for that is the interest of the investors. The whale investors or investing companies know the potential of a country like Dubai and when Dubai starts paying in Bitcoin then for that they'll have to reserve huge amount of Bitcoin.
The Dubai Government will keep accumulating more Bitcoin so it can pay the citizens with Bitcoin, however if instead of Bitcoin they choose some kind of stable coin like USDT then that's not going to help Bitcoin at all, but I'm pretty sure Dubai is going to be a hub for cryptocurrencies and they won't avoid Bitcoin and they may also consider paying with some good altcoins as well.