Not at all. In RT, each company had a communications officer who carried a better communicator, plus a scanner or whatever they were called before they were just a generic auspex.
Librarians are intelligence officers, for sure. This makes the point though. In the below section from wd97, there are described communications officers and lieutenants. This was when Rick Priestly (and here, David Wise) still kind of thought that marines were the army. Since they turned out not to be the army, those ideas had to be streamlined by veteran sergeants and the modern librarium.
As with medical personnel, a chapter's field-communications staff varies according to the mission. Communications Officers, Astropaths and Psykers all fall within this section. The primary role of psykers is to maintain inter-stellar and inter-planetary communications. On the battlefield psykers provide psychic support as required.
All communications personnel are drawn from the Librarium staff. The Librarium is the nerve centre of any marine fortress. The three groups outlined above differ in the following respects:
Communication Officers are brethren (i.e. fully initiated marines) who have technical expertise as well as battle experience. A Communication Officer will usually have held the rank of at least lieutenant before re-training in the communication role. Communication Officers are in charge of all aspects of communications as well as the psychic members of the force. A Communication Officer may also be a psyker (see below).
Astropaths - are Imperial servants, members of the Adeptus Astra Telepathica, posted to marine units as part of the Imperium's complex communications network. An Astropath may hold office within the chapter, but is not a marine and is ultimately subject to the will of the Adeptus Terra.
Psykers - some psykers are judged sufficiently strong to remain whole rather than suffer the transformation into an Astropath. Such men are recruited into the various Imperial services. Some are recruited by the marines and undergo the complete bio-chem ritual which turns them into marines. Some chapters integrate psykers into company level, but the Ultra-Marines place all such individuals within the Librarium. That is not to say they are unused to combat. Psykers perform a vital role as psychic support troops for their brother marines.