Tl;Dr
When talking about the use on expletives on local or network-wide Meta, that are not about the name of tool, programming language, or the word itself on a language site, what do we understand by necessity to use expletives?
Are each community able to set a local policy about what "necessity to use expletives" means for them that supersedes the related SE Meta FAQ?
Here on Meta SE we have the tag profanity
Tag excerpt:
vulgarity, expletives, cussin'... Whatever you call it, it's not welcome here.
Tag wiki:
See the discussion here: Are expletives (cursing, swear words or vulgar language) allowed on SE sites?
Consensus is that foul language should be rare to nonexistent. While it may be necessary in some cases here on meta, if you have to ask then you don't need it.
Please focus your attention on
While it may be necessary in some cases here on meta, if you have to ask then you don't need it.
The linked thread on "here on meta" points to question with the following title
Copying profanities and obscene words on Meta
This question was originally posted to SO Meta and migrated to SE Meta. It has the following sentence
This question is a direct result of the editing and reverting done on an answer to Why was this edit approved? which, due to that, was locked.
And the answer regarding the linked question says (emphasis mine)
Unless you need it, don't use it. If you need it, don't worry about it.
The example that prompted this didn't need it - the vulgarity in question was plainly visible in the edit the OP linked to!
An example of "need" might be discussing a potential profanity filter, or perhaps the vulgar name of a tool or language. Even then, try to keep it professional; vulgarity for vulgarity's sake is what YouTube comments are for.
I've cleaned up the answer you linked to and unlocked it.
Unfortunatelly the "edit the OP linked to!" is not available anymore, as I understand because the migration process didn't include the question edits.
By the other hand IMHO opinion the necessity for posting an expletive on a local Meta's something that could be discussed on case by case basis when the expletive isn't available by any mean, in other words, if the expletive is available for ♦ moderators and >10k rep users by means of a link/review/audit tool, there is no need to mention explicitly the expletive on Meta.
Also I understand that this is network wide policy not a policy for only for SO where the the thread was originally posted.
A more recent post, What is the policy on quotes with profanity?, quotes the content of the first link on the wiki for profanity, the answer to tha question ends by quoting the quote made by the OP
If you can't effectively communicate what you need to say without resorting to lowest common denominator cursing, then keep it to yourself.