Of course I'm willing to guess that WWE has smaller sales than NBA, but at the same time WWE has literally no competition as far as I know, while NBA at least has Live, which in all fairness has been improving year after year.
Source: https://twitter.com/WWEgames/status/914956241297743872
There are no paid microtransactions in #WWE2K18. Info on unlocking loot cases via in-game currency is here: https://t.co/ZmJQQJ7Bin
The link points to a page with info on WWE 2K18, which says (among other stuff)
Unlocks can be earned through loot cases and progression in both MyCAREER and ROAD TO GLORY. Most Superstar parts and moves are locked from the start. Once an item is unlocked, it is then purchasable with VC.
And in some interview, the Executive Producer for the game said
“We don’t have purchased VC in our game”
It is set up like microtransactions, but they seem to at worse have pulled out last minute. So again, maybe a good sign that NBA 2K19 will scale back a bit with them.