I mostly agree with all of this - but the US government is already a fairly big user of o3b. Oneweb, in terms of what their terminals will look like, the slightly higher orbit, and the fact that they'll only be selling to enterprise/carrier/government users and ignoring the consumer end user, is already somewhat similar in business plan to o3b. I wouldn't be surprised at all if they make a serious effort to capture a good portion of US gov business from SES.

It is also highly possible that oneweb may sell the equivalent of a geostationary SCPC 1:1 transponder lease, or an o3b dedicated-capacity circuit, which might not be something that would be technically feasible with starlink. If you're coming from an environment of geostationary looking at $1200 per Mbps per month, anything looks good by comparison.