It's interesting - probably a good idea on an extra perk for even more spend, as in fact all they are offering is a bit more convenience as if you're spending USD40k then both of you could almost be ambassadors in your own right (and a year ago would have been). My spend won't hit that level for a while (though to be honest I am not that far off and could push it if I wanted to, probably finishing the year at about USD33k or something), but seems to add an interesting twist.
In my case, as my kids grow up, I have been debating how to manage this from a status perspective as we graduate from suites to two rooms (that may arguably be cheaper). My initial thought was going to start getting one of the kids to earn their own status, rather than my spouse who very rarely travels without me to a Marriott (due to company travel policy seeming to default to random no-chain hotels).
Now there would be the option to guest my account status to one of them, which could become very attractive as you then have an ambassador without the same nights requirements (granting lounge access for four/two rooms, more bonus points, higher upgrade chance etc.), whilst consolidating the spend on a single account (but this would require every check-out I'd be merging the bills together). The loss is that the +1 wouldn't be gaining any nights towards their own lifetime status then, plus any promotional bonuses wouldn't tend to accrue.
If they could create some kind of quasi household account where two people's spend consolidated towards the 40k USD it would be even more beneficial, as then the +1 would be earning their own lifetime nights.
Two final thoughts:
- I'm almost tempted to drop the USD10k now to get the amusement of hotel staff checking in my 3 year old ambassador kid, in the same way they tend to be fairly impressed she is a OWE, expensive amusement...
- Noting that I am not in the USA, so I can't just get a USD700 credit card to grant someone (over 18) Platinum status