Pronunciation of final -o
There is no contradiction; both of the statements are saying the same thing.


There is a final in Chinese that is pronounced [wɔ].
This is the final in syllables "luo", "ruo", "wo", "bo", etc.
It is sometimes spelled "uo" (as in "luo") and sometimes spelled "o" (as in "bo").
Specifically, it is always and only spelled as "o" following  b-, p-, m-, and f-.