I seem to recall a comment on a spec issue where the Firefox behavior was considered, but I failed to find it. [rtcweb-wg/jsep/issues/832](https://github.com/rtcweb-wg/jsep/issues/832) would suggest this is not an error and should be supported.
Bug 1531075 Comment 1 Edit History
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I seem to recall a comment on a spec issue where the Firefox behavior was considered, but I failed to find it. [rtcweb-wg/jsep/issues/832](https://github.com/rtcweb-wg/jsep/issues/832) would suggest createOffer wo/transceivers should be supported.