The VFR stuff is always optional for ATC. VFR aircraft can request those things and ATC will usually accommodate, but it's workload dependent and ATC can and does decline, that's the whole tradeoff of flying under VFR rules. I'm less sure on the others, but I'm pretty sure they're all optional as well for ATC.
Now the difference might be that ATC will be more likely to deny these requests, which could be somewhat disruptive to flights that were expecting to be approved. But it should never be assumed so hopefully they have backup plans.
Now the difference might be that ATC will be more likely to deny these requests, which could be somewhat disruptive to flights that were expecting to be approved. But it should never be assumed so hopefully they have backup plans.