My experience of these people is it's not so calculated. They are quite a self important, at times ignorant set of people.
By chance the YOUGOV MRP got it close to being right last time. That looks increasingly like a stab in the dark. It was actually because they got the top line figure correct.
The prediction was consistent with all the other companies predictions thus far. We are seeing herd mentality with the election predictors now, who refuse to accept anything other than 2017 being a one off, and it being solely down to May being awful.
I did state all this at the time in 2017. I remember saying May was awful and these same experts sneer and make out she was the most popular PM since Thatcher, and I was a crazy Corbynite in a bubble. Now they preach the same thing back to me, without a word of humility of how wrong they were, not just that how bad she was, but how that singularly means it can never happen again.
Behind closed doors, the people that matter, Cummings and his team are majorly freaking out currently. They have no idea how Corbyn remains so popular.
There is the potential for the 2019 result to be more out than the 2017. If it proves to be, wait for the tantrum that follows.