A, it's an interesting question. Thanks for sharing.
The short answer to industry tiers is no. Also, beware of vendors or re-sellers trying to put a competitor product in a lower position.
Longer answer: being 'tier 1', i.e., in your description, 1,000+ cameras, typically requires supporting the following features:
- Enterprise management
- Health management
- Deep third-party system integration (access, intrusion)
- Rules for triggering actions / responses
- Alarm / event management
- Network video wall
- Server / recorder redundancy or failover
- Video analytics and LPR integration
- Edge storage support
- Well documented API / SDK
- Sophistication / completeness of each of the above
- Actual track record of in-production large scale systems to verify that this all really works
As for Genetec / Milestone, Milestone tries a lot harder to win small to mid-size business than Genetec (in terms of pricing and packaging). So certainly Milestone is generally more appealing to small / medium than Genetec.
However, Milestone does have their own 'tier 1' type offering - Corporate which has pretty much all of those features. To that end, it is hard to say that Milestone is not 'tier 1', in your terminology. Whether Genetec is better or worse than Milestone is certainly more complex to answer and depends on one's needs.
If you were looking at systems that work at the 1,000+ level, I'd start by examining that list, what you need and what the VMS vendor actually delivers.
I know of no such industry standard definition related features/capabilities. Manufacturers putting themselves in "Tiers" are simply doing so for marketing reasons. It is designed to confuse people IMHO, to make an inferior solution appear to be a superior solution. I suppose it is what makes things interesting.
While I can't say that it's published or official, but in my neck of the woods -- the Pacific NW -- the tier system for VMS solutions (and for cameras, or any security product) has been widely used for several years. However, rather than tiers being used to designate the size of the targeted or most appropriate solution, it's been used to designate the calibur of manufacturer. I.e. Axis, Sony and Arecont are Tier 1 camera manufacturers while less accepted / proven brands like the Chinese brands, new players or even older analog guys that have fallen (like Pelco, Honeywell, etc.) have been Tier 2, 3 or beyond. It has helped illustrate to customers the difference between reputable camera brands and the cheaper brands in a market that continues to be commodotized.
Tier 1 VMS solutions in the NW are typically Genetec, Milestone, OnSSI and Exacq, though Avigilon sometimes finds it's way in if the customers don't mind more closed solutions.
Again, this is purely subjective and there's no way to prove any of it, but that's the way the terminology has been used.