hi Drone,
…please don’t think I’m interfering here but I was curious about this myself so got in touch with York about it a little while ago. Finally, this is their reply from the Chief Exec’s office:-
”Thank you for your email.
We were racing on the original line so the distance of the race was as advertised.”
..you trust that I take it? or not… 
Hi UM
Not interfering at all, such in-depth missives from racecourse execs to we ‘stakeholders’ are welcome and very valuable…they know you know 
But strangely, I feel none the wiser 