To echo what others have said - the times between gates opening has never been an issue with the Spire. There was always time to complete it and shorter gate times makes no difference to that. In fact it's useful to use the whole time to replenish coins and supplies.
The explanation seems to be saying that changing the diamond amounts on offer counter-balances the "benefit" of shorter timers, which makes it seem like we will be worse off overall, but I can't see what these diamond amounts are being increased or decreased to so I'm not sure yet whether this is an improvement or a nerf.
I don't remember the feedback being referred to. Was this a specific thread on this forum? More diamonds is good, of course, but it would have to be quite a lot more to be appealing. If you are saying that the prize for completing the third round will now be somewhere north of 500 diamonds then perhaps this is a good thing, but I refer you back to my second paragraph.