According to an article by Yoni Ben Menachem written on January 10 published by the Jerusalem Centre for Public Affairs, "Two weeks ago, Hamas leader Ismail Haniyeh claimed he had learned that, in President Trump’s new plan, an overhead bridge would be built from Abu Dis to Al-Aqsa so that Muslims could freely come to pray at the mosques on the Temple Mount."

Menachem describes Abu Dis as " the point that connects the northern and the southern West Bank. It is also the eastern entrance to Jerusalem, and in the other direction, it leads down to the Jordan Valley. According to the Oslo agreements, it is part of Area B which is under Israeli security control and Palestinian civilian control." http://jcpa.org/palestinian-capital-abu-dis-ramallah/

It should be remembered that in 1995, Abu Dis was mentioned as a possible Palestinian capital in understandings reached between Abbas and Yossi Beilin. In 1996, construction began in Abu Dis for the parliamentary building of the Palestinian Legislative Council. (One-third of the building was constructed on land within the municipal boundaries of Jerusalem, according to Ben Menachem)

Abbas is saying that Abu Dis as a Palestinian capital is a non-starter, but behind the scenes the New York Times reported that following Trump’s declaration of Jerusalem as Israel's capital Saudi Crown Prince Mohammad bin Salman demanded that PA Chairman Mahmoud Abbas agree that in the permanent settlement, Abu Dis would be the Palestinian capital. 

Not only that but according to the New York Times when Abbas went to Saudi Arabia this past November, Crown Prince Mohammed Bin Salman demanded that Abbas accept a plan whereby the Palestinians would get a state but only in noncontiguous parts of the West Bank with limited sovereignty over their own territory. Under the plan,the major  Israeli settlement blocks  in the West Bank,  would remain part of Israel, and the Palestinians would not be given East Jerusalem as their capital, but Abu Dis There also would not be any right of return for Palestinian refugees and their descendants to Israel.

https://www.nytimes.com/2017/12/03/world/middleeast/palestinian-saudi-peace-plan.html

In effect, the Saudi Crown Prince seems to have accepted the "Likud peace plan", which is no doubt why Netanyahu has been saying for some times that behind the scenes Israel is not so isolated. Both Israel and Saudi Arabia are concerned about Iran, and the Palestinian cause does not appear to be high up on the Saudi priority list.

I rather doubt that the Palestinians will  accept Abu Dis as their capital, but it is now clear that when Trump tweeted recently that "we have taken Jerusalem off the table" he meant it.