Yes, I did register for the webinar .. I'll do my best to represent the weather website hobbyist interests from a user and developer perspective. I hope it's not prophetic that they picked Microsoft Patch Tuesday in December for the webinar.
I, too, use Allison House feeds for my GRLevel3 radar, and I'm sure they'll continue undiminished by the changes since they likely have an agreed-to set of feeds.
Like Wim, I'm concerned that the NWS API canonicalization of data calls has resulted in requiring more-than-one access to retrieve the needed data, each of which counts on a rate-limit scheme. Wim's points about shared webservers is also good -- with a lot of personal weather websites hosted on shared servers, they generally have one IP address as an egress point for the queries by the scripts, so a rate-limit by IP address could take a bunch of websites out. If they instead insist on an API key in the query, then it would be possible to separate those queries by requestor. The API developers for api.weather.gov have intimated that a API key is a future project.