or may be replaced by Mandarin
As a Mandarin speaker, I think that's unlikely. China has enough of a problem (literally) enforcing Mandarin within its borders. Natives have such trouble understanding regional dialects that all TV shows, even those in the equivalent of received pronunciation, have subtitles.
Beijing Hua is probably the most famous example of this where Beijingers smash everything together at lightning speed and add the reflexive -r (儿) to everything as if they were west country pirates. "I don't know" in Beijing hua is pronounced "Berrr Dao" (imagine the London "blap" sound) as opposed to the standard "Bu Zhidao" (不知道)
Interestingly, the pronouns for he and she in Chinese are pronounced the same, but written differently. 他 / 她
Mandarin's use of homophones is also problematic for non tonal speakers.
As said before, this problem vanishes if you write in a language like Hungarian, German or Japanese.
Japan has gendered pronouns, even down to "I" -boku (or ore) / atashi - male / female. Watashi can sound too formal or effeminate if used by a man in familiar company.
He / she in Japanese is かれ / かのじょkare / kanojo
Japanese also has gendered sentence forms, such as in imperative sentences where males add a set of articles at the end of a sentence - males take the standard imperative form and add「な」or「ろ」. Females will add 「て」.
Foreigners are usually taught standard Japanese forms which can sound "funny" or "effeminate" to Japanese speakers (don't shoot the messenger!).
German has male and female pronouns - Er / Sie - as well as gendered nouns. Gender also affects their noun forms too, with suffixes that match the gender of the noun (eg -age / -ik / -in / -nz etc. are all feminine noun suffixes).