Hey @bobthebear, love that you asked! Challenges aren't gone - we're just introducing some new ways to get involved (like Builder Talks and an upcoming build-along week in June👀) and thinking about how challenges can be part of the bigger mix.
We might space them out a bit more or weave challenge elements into other events, but they're still part of the plan. The build-along, for example, will have plenty of chances to show off your skills, earn rewards, and maybe pick up a badge or two 
I'll take this as a strong vote to keep them coming! Any past challenges you really enjoyed? Or something you'd be excited to see?