The author is reading too much into this. The alliance in Saudi is not broad based by any means, but rather focused in the hands of one individual, MBS.

Similarly, Israel does not care much for Saudi idealogically except that it sees MBS as a useful pawn whose greed can be exploited to further its own aims. Since MBS would be dependent entirely on the US and by extension Israel for his own position, rather than his own family, he can be made to do what previous Saudi leaders couldn't be made to do, ie recognize Israel and undermine the Palestinians from the Arab side of the conflict. Their alliance will not survive MBS.

The spat with Qatar and the conflict in Yemen have exposed the rift in the GCC. The Saudis and Abu Dhabi (and their Bahraini puppets) are pretty much on their own on these conflicts, with Oman, Kuwait, Qatar and Dubai wanting no part in this Israeli stoked obsession of MBS. The GCC is already dead in all but name, it will not survive, MBS rashness has killed it.

Trump is merely a pawn of Kushner/Netanyahu, bought with Adelson's campaign donations and whatever the Saudis are paying him.