Telepathy

technically not breaking the rules is very much a fey thing, so id say yes. they are technically not breaking the contract.

Quote from C3ii >>

I would think the creature needs to be known to the telepathic monster, but if that were the case why would they specify not needing to see the contact without establishing another way of knowing the creature's existence. 

 Think of a leader that has Telepathy, but its minions do NOT have Telepapthy.  Even if the minions are in a nearby bunker, the leader could rouse them with telepathy and direct their actions without needing line-of-sight to them.

Thri-kreen Telepathy

Without the assistance of magic, you can’t speak the non-thri-kreen languages you know. Instead you use telepathy to convey your thoughts. You have the magical ability to transmit your thoughts mentally to willing creatures within 120 feet of yourself. A contacted creature doesn’t need to share a language with you to understand your thoughts, but it must be able to understand at least one language. Your telepathic link to a creature is broken if you and the creature move more than 120 feet apart, if either of you is incapacitated, or if either of you mentally breaks the contact (no action required).

I believe, if I remember correctly that is, that Telepathy is a language, so you have to know a language to understand it in telepathy.

Quote from LightEmUp >>

I believe, if I remember correctly that is, that Telepathy is a language, so you have to know a language to understand it in telepathy.

 

Telepathy is not really a language, though it does appear in the "Languages" area of monster stat blocks.

The rules on Telepathy in 5.5e explicitly say that you do not need to share a language with someone to communicate with them telepathically, though the other party does need to either be telepathic themselves or know at least one language in general.

Telepathy does not require the two creatures communicating shate a common language. I.e. when the aboleth who only speaks abyssyal speaks telepathically with a player, the player understands.

However, specific overrides general, therefore, the telepathic feat says you must speak in a language tbe recipient understand. 

Quote from SunIsGettingRealLow96589 >>

Telepathy does not require the two creatures communicating shate a common language. I.e. when the aboleth who only speaks abyssyal speaks telepathically with a player, the player understands.

However, specific overrides general, therefore, the telepathic feat says you must speak in a language tbe recipient understand. 

I'm not sure how the feat comes into play, but you are correct about Telepathy in general. A specific source of the ability may override it.

As wagnarokkr mentioned, it is not a language in its own right.