The Richmond Park changes are actually a downgrade from where things are the moment, which is essentially completely traffic free. Apart from having the gates mainly closed, there are also barriers at strategic points that force everyone into a single lane which are fine for bikes paying attention but would be quite the challenge for more than one car at once.
As a result there are so many different people out on all sorts of bikes it’s unreal. Lap records are out the window just because it’s not cool to fly past 10 year olds or their grandma’s out on bikes, let alone the traffic control measures.
It’s delightful, and probably going to get worse again once they let some cars in.