Yes, as of February 2021, all US Toll-Free numbers purchased through Twilio can send/receive MMS messages to and from end users in the United States and Canada.
For details, see:
- Information and best practices for using Toll-Free SMS and MMS in the US and Canada
- Toll-Free SMS and MMS Messaging Throughput (MPS)
Toll-Free numbers from countries outside of the US are Voice-only, and are not capable of SMS or MMS messaging.