Providing you have properly supported and screwed the board back down adequately it generally isn't necessary, and in any case it won't achieve much because you presumably have some 3mm gaps around the replaced part - and wood adhesives are not fillers. If you wanted to use glue you should have used it to glue down the replaced piece(s) onto the joists or bearers, where it will make a difference
If you do want to seal the gaps I'd suggest some foam underlay, Fossa Caulk Saver, etc pushed into the gaps might be a more sensible approach than a permanent filler - you never know, you may need to lift that floor again in the future...
), unless that is an OCD joiner has taken the time to do the cut out really neatly (plunging saw and saw guide) and replace the same way. If it really needs to be good replacement I cut out, but replace with a new piece of flooring trimmed to be a near perfect fit in the 'ole. That does benefit from glue on the edges, but it takes a bit of skill and patience (based on how few site guys I've worked with who can do it right). Anything else is really bit of a bodge
