A thawing in Brexit negotiations?

There could, at last, be some thawing in the frozen Brexit negotiations. The key issues remain the divorce bill, the Irish border and the rights of EU citizens in the UK.  But the 27 EU leaders suggested they’ll start talking among themselves about a post-Brexit trade deal with Britain. In turn Theresa May hinted paying out more on the divorce bill. So what’s behind the cheerful mood music if nothing substantive has changed? Does the EU fear Theresa May being thrown overboard in favour of a more bullish Boris Johnson?