20 points ahead in the opinion polls the UK Prime Minister could not resist calling an election but there are dangers in this. Previously with both the Conservatives and Labour having supported a Brexit referendum, they were obliged to support Brexit even though the majority of the MPs didn't want it. Despite what Teresa May had said both Labour and the House of Lords offered minimal obstruction to Brexit. After an election though MPs are no longer obliged to follow Brexit if their manifesto said otherwise. The calculation of the Conservatives is that they will gain more seats from Labour than they will lose to the Liberals but its unpredictable as voters will vote both according to their normal Left-Right bias and also a new Brexit-Remain consideration so normal voting patterns do not apply. Despite Article 50 being triggered nothing irrevocable has happened. If a UK government said oops we didn't mean it, Europe would gladly accept it.
About the only plus from my point of view is that it will force Scottish voters to decide what they really want. Many voted SNP without wanting another referendum so I'm expecting the SNP vote to fall. The prospects for Scottish independence are less good than they were before. The price of oil has halved and joining Europe with the rest of the UK outside would lead to currency and trading problems. But its not entirely a rational consideration.