I'm happy either way. If there's no requirement to use each compound at least once, I look forward to having multiple tire types available.
But I really dislike telling teams they must use each tire type. The officials don't tell them they have to make one run with only half a fuel load; or that they have to drive 20% of the race with a set of specific chassis settings and then change them for the rest; or that they have to run part of the race with the power steering disabled. Tire choices shouldn't be required to be managed any differently.
Give the teams options, not requirements.