Currently I have the following Amex cards:
Amex Hilton Aspire
Ames Delta Skymiles Platinum
Amex Delta Skymiles Reserve
Amex Green
Business Green Rewards
Business Gold

I received (in the mail) an offer for upgrading (I'm ASSUMING it's for the Amex Green card, not the business ones) to Gold/Rose Gold for 40k MR points after 2k spend in 3 months.
I looked at the booklet and read the paper additional disclosure sheet and cant' find any Llifetime language in it.

If I recall correctly, I can accept the upgrade and I would still be eligible for the regular Gold/Rose at a later date (new application)?

Is this upgrade offer decent?