I perfectly understand that has is more frequent name than hasOwn for this shortcut, but we have Reflect.has which works like in operator. The rest Reflect methods work similarly to Object methods - we should avoid this inconsistency. Also, I think, the method name should point to check own properties.

Edit from @jamiebuilds:

This proposal was presented to TC39 on April 20, 2021, where it went forward to Stage 2 but the name was left in question. This issue should be used for discussing the method name further.