We allow for comparison of Wikibase types (e.g. WbMonolingualText) but comparisons for not Equal does not give the expected results.
To illustrate:
import pywikibot as pwb
A = pwb.WbMonolingualText('Same', 'en')
B = pwb.WbMonolingualText('Same', 'en')
C = pwb.WbMonolingualText('Different', 'en')
A == B # expect True
> True
A != B # expect False !!
> True
A == C # expect False
> False
A != C # expect True
> True