Currently, Adobe Launch allows 3 kinds of hosts: Akamai, managed by Adobe, and SFTP.
For a CDN host, only Akamai and SFTP are viable options. (For SFTP, this assumes that the CDN replicates the scripts found in your SFTP destination.) So the only external CDN is really Akamai.
Depending on one external CDN as a host is dangerous. If something happens at Akamai, it disables all Launch scripts hosted there. Also, clients may not necessarily want to use Akamai for whatever reasons.
Idea: partner with other CDNs to allow hosting from them, e.g. Cloudflare.