I will appreciate further explaination about this, which wallets are non-node wallets?
Essentially, anything that isn't Bitcoin Core isn't a full node.
Seems to be not correct as there are others implementation of bitcoin nodes that can be called "full". Look at
https://coin.dance/nodes Sure those nodes that based on Bitcoin Core are the most numerous of all existing bitcoin implementations however they are not unique.
Correct, and I said as much in the very next sentence after the one you quoted. Yes, there are a number of other implementations of full node software, but given that all the minor implementations combined only make up around 1% of all full nodes, with around 99% of full nodes running Bitcoin Core, then when discussing the difference between full nodes, light wallets, and custodial wallets with a newbie who is unfamiliar with these concepts, then it easier to simply ignore these other implementations.
I often find in bitcoin, when explaining new ideas and concepts to newbies it is better to just focus on the main and relevant points, rather than get bogged down in the (often irrelevant) minutiae.