An even better example, of course, is Cloudbleed, but I guess we've all agreed to pretend that never happened?
Could it be I'm using an alias of Cloudflare@mydomain.industries?
Edit: Attempting "cf@domain.industries" and receiving the same error. Assuming you're accepting .industries registrations, it could very well be my corporate firewall blocking requests to something. I'll attempt again this evening from home.
You are correct that their CTO has submitted 16 posts this week (not all of them from their own blog), but I don't see the harm in that: less than half of them attract any comments at all and quickly slip beneath the waves.
Also, to be fair, it has been an unusually busy week, as they had a "Crypto Week" during which they announced something genuinely interesting each day, and their 8th birthday was a fair excuse for a navel-gazing post.
Aside from 1(techcrunch) they are all just posts of their own blog. I would call 15 submissions about your company in 7 days excessive.
If more people start doing this the danger is that HN gets reduced to just another marketing channel. I think that's a reasonable concern.
The majority of these posts tend to go into deep technological explanations, making it a good fit.