As far as I understand, there are sets of rules to be observed as a monastic monk and I'm not sure if TV, radio and other source of media is allowed?
Just curious to know, no offense.
A monk can appear in all social media, but there are, according to the Navakovada, some things he cannot talk about, if certain conditions are not met. Since he does not know whom is out there doing what, he might choose not to teach the Dhamma.
This is a bit of a grayzone, so it is up to each monks own evaluation whether he will do it or not.
Householder Sunset_Limited, interested,
a monk serious in taking only what if given in faith, without strings, may use social medias to teach if given, invited.
In regard of online social medias such will be very seldom the case and he is not able to get into contracts or take things with strings binding him. It would be also not proper to use third part, not given maintained recources, can not relay one common folk given rights (for duties or getting bond).
It's also improper to share Dhamma as a means of trade, direct or indirect.
How ever, to draw cases form the Vinaya, he might make shortly make use of such, similar the Buddha allowed to approach places of common charity alms giving for two or three times.
General the case of teaching not able to perceive others proper or improper regard is problematic since Bhikkhus would not be allowed to teach people showing marks of disrespect or disregarding attention. People are reading and watching in what ever situations... even on the toilet!
As long as not perceived... good, an escape, but not really good for freedom of remorse.
One might also perceive others as sick or not capable to go on, and modern world is at large to be regarded sick.
Some advices therefore on [Avatar and User placements](Avatar and User placements - Avatar und Benutzereinstellungen).
It's also not proper to disturb in medias which have different interests and seeing, watching, reading Dhamma next even porns or low entertainment, market... even encouraged to such places by monks... how inspiring whould such be, how dangerous for both?
It's surely because there are many not ashamed in all this things that there are nearly no proper places dedicated for the tripple Gems and where monks are proper invited. Even so called Dhamma places are actually not accessable, welcoming and inviting monks! Not to understand as claim but to possible see your own situation around you might be used of and not aware.
To found such places, found and give the foundation for such is not only of high merits but also that difficult to perform.
In a world that does not fear the debts of consume, one is really blessed if tracing fundamental wrongs and starts to understand the requirement of generosity at first place.
There is all proper place for gratitude toward those who make one receive Dhamma or engage in other merits on proper places, proper circumstances, at least also toward your past own sacrifices, which caused you to be touched and come this here and possible further, into borderland.
Some possible inspirations also here, in an older meta-topic: Would it be of interest to get answers from Monks and Nuns?, longer time ago.
At last but not least, from the highest blessings:
To be patient and obedient, to associate with monks and to have religious discussions on due occasions — this is the greatest blessing.
Mudita! Yet be also clear that ones gained merits are not for sure, decay, and required inwardly and outwardly nourishement to die not off as fast as touched by past.
One may feel always given to make use of given possibilities here, at least, even and of coures welcome, if just taking as inspiration to take on of what is difficult to take on and since beginn and enter of the rains tomorrow, here also a best wishes, blessing and encouragement for all around and touched.
(Note that this is not given for trade, exchange, stacks, entertainment and akusala deeds, but as a share of merits and to continue such for release)