Don't think it's quite accurate for me. Particularly as I don't think that the supposedly 'progressive', 'left-wing' positions that some claiming to be on the left are now pushing for are in fact remotely left-wing at all. And I doubt that many of those pushing those views most strongly now would have been your 'average' left-winger a decade ago either; I think many of them were (are) far left/right extremists - MRAs, misogynists and racists.
I'll note that, in my comments below, I approach this (like Hadley Freeman in her recent articles about the Guardian), as a left-wing Jewish woman, i.e. someone who has seen the left's abandonment of both its previous anti-racism/anti-misogyny stance as doubly painful.
Going back to the diagram - images.wsj.net/im-535576/social - rather than a straight line, which implies that far left and far right are as opposite as it's possible to be (definitely not the case!), I'd present it instead using the horseshoe or circle model - where both the moderate conservative on the right of the point marked 'centre' and me and the other left-winger to the left of it, would all have been, until very recently, approximately the same (moderate) distance from the centre. Meanwhile, at the opposite extreme (literally), as far as you can get from the centre, there were always pockets of grimy Militants, Trots, Fascists, National Front etc - but in sufficiently small numbers in the UK in my lifetime and sufficiently powerless, that they could be ignored.
Unfortunately, events since 2015 (Corbyn) and 2016 (Brexit) have propelled extremists on both sides much closer to the fringes of power. And in Corbyn's case, nearly into power. So I'm not sure how much your average left-winger has actually completely changed their values in the last decade? But a toxic combination of extremist entryists, extensive and systematic use of violent threats and physical attacks, constant shouted insistence on No Debate, It Was A Scam, failed and biased moderation in the public square, eg Twitter etc, and media capture have made it almost impossible for people on the left to find and connect with other 'normal' people on the left, or discuss the issues. In this, we owe MN a huge debt, for providing one of the very few public spaces where ordinary women can discuss, challenge, find out, about the implications of these new supposedly 'progressive' approaches - particularly on women's rights.
Labour now has a huge amount to do to remind itself of what being left-wing actually means. They're slowly getting there on antisemitism (hopefully); still a long way to go - one area where it was clear that there was zero difference between the far right and far left (as evidenced by David Duke of the KKK fangirling for Corbyn).
But Labour still has a very long way to go, to remember that the rights of the female half of the population matter too, and that women are actually people. With votes. As well as inalienable human rights. At some point - will the catalyst be the undoing of Mermaids? - they will have to face up and come clean on their role in encouraging these attacks on women's and children's rights and safety. Sadly, they have a precedent - let's not forget Labour a generation ago having to shamefacedly walk back their involvement in PIE.