I believe it was posted somewhere on here that the personal ambassadors have a supply and choose who they will send them to with a personalised email? Saying "enjoy your current/imminent stay at..." seems a pretty easy piece of personalisation to use in that message if you have such a stay showing in your account, even if it wasn't the main reason for being selected. I hadn't actually had any contact previously with my Ambassador when I received the voucher (they had recently changed), but then I received one last year too before personal ambassadors had been reintroduced. There's probably some rationale but I guess it may vary slightly from amb to amb.

I didn't receive any playing cards or dog toys though, so perhaps it all balances out in the end...