Originally Posted by yurtripper

You will have Gold when the status resets in Early 2019, unless you qualify for Platinum this year through 50+ nights or 25+ stays at SPG properties.

What has NOT yet been established (despite numerous claims to the contrary) is what your status will be from August 1 till Feb 2019, assuming you matched your SPG Gold to MR Gold. Personally, I think it will be Platinum but the main thing is that we still don't absolutely know for sure - and people claiming otherwise are selectively using argument from authority to support their case.

If you haven't matched your accounts, and your current status is solely based on SPG recognition via your Amex plat, you will definitely be Gold from Aug 1.
The last possibility (unmatched accounts) may seem far-fetched, but that is not necessarily the case among the general public, which is why various Marriott VPs have been calling for people to ensure their accounts are linked before August 1. This is another thing that leads me to suspect that SP Golds matched to MR will get Platinum from August 1 until the time of status reset.