I would say it's very relevant, and explains why Cameron trounced the more Eurosceptic Davis.
In the final MP's round Cameron got 90 and Davis got 57, members mimicked this with 66% to Cameron and 34% to Davis.
Again in 2019 Johnson got 160 to Hunt's 77, and members fell in line with 66% to Johnson and 34% to Hunt.
Not a big sample size but I reckon if there's a similar margin in the last two this time, members will broadly follow it.
It gets more complicated if it's a close result like 2001 but I don't think it will be.