If you are wondering who is the commission, the United Nations has a good overview on their past and accomplishments.

They all don't have a history of Anti-semitism, as claimed, but more along the lines such as:

• Human rights in Gambia vs. Myanmar
• Human rights on housing
• Inquiry into Detention in the Democratic People's Republic of Korea.

These guys are no joke, they have done this before. But more importantly, the comment that got them suspended?

“We are very disheartened by the social media that is controlled largely by, whether it is the Jewish lobby or it is specific NGOs, a lot of money is being thrown into trying to discredit us,” he said in the interview.

But above all that, the excuse that Israel is using is:

When asked by The Times of Israel what these claims were based on, Haiat said, “The commission of inquiry is there to investigate Israel without any time limits, unlike any other commission of inquiry from the UN system.

Keep in mind, not even the investigation team knows how long it will take, so of course there won't be a time frame. And they work for the UN, why do they need one?