It's not template node specific - it is the way the whole dashboard works... Only messages arriving from a UI widget will contain a valid socketid. The dashboard will then (if the socketid is intact) then only reply back to that socketid - precisely so you can do things like only set an alert/notification popup back to that socket (otherwise everyone has to hit OK/Cancel which gets very annoying) - or you can use it to send a ui_control back to only one socket so they can switch tabs without switching all screens.
So if the socketid exists the msg gets sent to that socketid - if not (ie has been either deleted deliberately or a new message generated eg via node.send) then the msg is sent to all.
So yes - working as designed.
