"Time will tell" is indeed the best response. I welcome the UBS news as much as anyone but it is not as clear as you might think. Here is a clipping from the telegraph report which said the move of 1000 staff was looking less likely:

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While UBS has softened its stance on the number of jobs that are likely to move, it is still hashing out plans to protect itself.?Mr?Ermotti looked to soothe concerns for London staff on Friday by saying that it was his?"target"?to "keep as many people as we can in London".?

UBS is one of the last big banks to decide on where it might relocate people post-Brexit, with London staff last week asked to rank whether they would prefer?to relocate to Amsterdam, Madrid or Frankfurt, sources told Reuters. ?
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So a welcome change in the likelihood of these 1000 staying, but still up for grabs in the end.