Xbox one games with gold member - Xbox 360 GWG trying to charge $$$

Did I miss a change affecting the GwG program on the 360, such that an active XBL Gold membership must be maintained to access the games you've downloaded on the Xbox 360?

I understand that an active XBL Gold subscription is required for access to the
Xbox One GwG games after you've claimed them, but I'm not findng reference to that type of change to the 360 GwG program.

I copied the footnote explaining the Games with Gold program from the existing webpage:

"**Games with Gold Offer for paid Gold members only; Active Gold membership required to play downloaded Xbox One games. Each participating game (selected by Xbox) available for download from Xbox Store during specific window; available games
may vary by country. Some titles may only be available for download by adult account holders 18+. Kinect and/or hard drive required for some games. Offer available in all Xbox Live countries where Xbox Live Gold memberships are supported. Offer is non-transferable,
not redeemable for cash, and cannot be combined with any other rebate or offer. Offer terms and availability subject to change. Taxes, if any, are the sole responsibility of member. Download charges may apply as set by your ISP. For Xbox Live Terms of Use
and system requirements, see xbox.com/live."

My games for gold is trying to charge me for some games it let me download xbox1 games but is trying to charge me for 360 games my payment method is valid and like i said no trouble with xbox1 games just 360 castlevania

Are you sure that you are getting charged? Xbox 360 GWG needs a payment option, but if you check the price you should see that the game is "free".

There's no promotion or anything that I know of where you get those particular games by upgrading to Xbox One.

All of the games you listed were GWG at some point (up to 2 years ago). Did you redeem those Xbox One titles through the Microsoft desktop website while they were free? That would be a way to redeem Xbox One GWG titles if you only had an Xbox 360. Also,
Xbox One GWG titles are only accessible in your library while your Gold subscription is active (as opposed to Xbox 360 GWG, which remain playable regardless of your Gold status).

Coming up in October, Xbox Live Gold members can look forward to three new free games on Xbox One and Xbox 360

is the statement, if you asked me to go into a shop and buy three shorts and ties would I get 2 shirts and 1 tie? I wouldn't

Imo the correct statement is, there are 3 new games on gwg, 2 on the 360 and 1 on the xbox one, but thats not what it says.

The Gold subscription requirement has been in place for four years, since Games With Gold was expanded to Xbox One. Xbox 360 GWG titles are still yours to keep forever, even if your subscription lapses, and can still be installed and played on Xbox One.
Xbox One GWG titles require you to maintain an Xbox Live Gold subscription; if you let your subscription lapse, you would have to buy the games outright, or renew your subscription.