The Daily Telegraph's Brussels correspondent, James Rothwell, reports
"EU source says gearing up for scenario where Boris/Raab tries to change Brexit deal on first trip to Brussels, and fails, then calls an election. At which point a change in the make-up of parliament could illustrate a way through deadlock."
This basically fits into one of the scenarios pointed out earlier here. As mentioned then, it's no different than May being in office and calling for a general election. Just that with a new prime minister, the likelihood of that has increased in order to secure a new mandate.
