That JC is and always has been a Eurosceptic is something that people who work with and have known JC for years frequently say and have never disputed yet a bunch of people online know better, I'm sure.
Corbyn's big customs union speech has a whole section in which he laid out his foreign policy perspective which includes a defence of left Euroscepticism for goodness' sake.
Also let's just sense-check it here: the contention seems to be that the EU became more attractive between July 2015 when JC had not "closed his mind" to backing exit and June 2016. I mean, why would that be the case?
It is true to say that JC's Euroscepticism is not a useful starting point for understanding why Labour has the EU position it has now. But that is a wholly different position from "JC is not a Eurosceptic".
