Hi there,
Unfortunately the licenses from RPG Maker Web and itch.io are two different products. As the RMWeb version is an RPG Maker only license that takes cuts for Degica, KDKW and Steam, and is also cheaper than the itch.io version, it is a separately published product that provides us with less revenue. Therefore the itch.io version of the product provides more benefits to the user such as being engine-free and receiving updates, in order to encourage users to buy their license directly through ourselves.
Sadly this means they are technically separate products, and the RMWeb version does not receive the same updates as the itch.io license. Sorry for any inconvenience this causes you.