It's also an attempt to not give reasons to the British government to red-light the acquisition. If you read the BBC, lots of British personalities (including the founders of Acorn and ARM themselves) have been extremely critical about the whole deal and are vehemently lobbying the UK government in order to stop it and bring back the company into British hands. If they let slip that they considered moving even a single job out of the UK, they would have basically confirmed what everybody was saying. Probably the UK government won't do anything because due to Brexit they desperately need trade deals and new partners, so they need to lick the US's arse and avoid angering Donald Trump, but still, it wouldn't be wise nevertheless.
> Probably the UK government won't do anything because due to Brexit they desperately need trade deals and new partners, so they need to lick the US's arse and avoid angering Donald Trump
That doesn't mean they need to approve the purchase - it just means they have to stall until they know the outcome of the election.
There's no chance of a trade deal being done before the election, and waving the sale through to earn Trump's favour is pointless if it's Biden they're making a trade deal with.
It was clear SoftBank didn't give a damn about ARM, they only bought it to grab some of the sweet monies they were raking up and pretty much left everything as-is. Not so much for NVIDIA, which is a big player in the industry and is American.