HHonors?
I am assuming you are talking about the HHonors rewards. I was a Diamond VIP for a small time and I have to say; no it is not automatic. First, there has to be an upgradable room, normally at Hilton named hotels that have towers/executive levels. (A one bedroom to two bedroom suite is not consider an upgrade. Upgrade is more like bottom floor no view to higher floor with a view. This is really geared towards business travelers) You have to ask when checking in if there is a upgradable room available. (It must be available for the whole stay not just part) Lastly, I have done upgrades as a Gold rewards member, so it really does not make any sense to try to achieve Diamond status. If it happens, it happens. The only worth while benefit at the Gold and Diamond level is the complimentary breakfast, and some places mid-afternoon snack. The best benefit, regardless of level, is the mangers reception where the first couple of alcoholic drinks are free.
Remember this is for hotel stays and not timeshare stays. The HHonors VIP levels does nothing at the timeshare resorts. For example, if you where staying at the Lagoon Tower at HHV, you will not get a free voucher for breakfast for being a Diamond VIP. However, if you convert your HGVC points to stay in the Hilton Hotel, then you are eligible for the free breakfast, up to two people.
Also, let me be the first to say, it is really not worth buying HGVC timeshare retail to become a Diamond VIP member. In the long run you will save much more money buying resale, and forgoing the HHonors reward status.
Hope this helps
Deros