Those actively involved in lateral communication, which cuts across chains of command and coordinates departments, are called

Those actively engaged in lateral communication that cuts across chains of command and coordinates departments are called boundary spanners.

They link separate units, carrying information sideways so that departments stay aligned.

Man of the match is a sporting label with no place in organisational communication theory.

Gatekeepers of command is not the recognised term, since gatekeepers filter information flow rather than span boundaries laterally.

Wicket keepers is again a cricketing role wrongly borrowed, unrelated to cross-departmental coordination.

Boundary spanners are vital for horizontal coordination across a formal hierarchy.