Intercepting messages has, over the years, been repeatedly considered and discarded as a possibility.
However, gathering information about a city at a distance would surely be something useful.
In general, I would consider the sabotage aspects of the current infiltrator strong candidates for being retained, and possibly even improved somewhat, given the changes I'll be making to the rest of the class.
Assault would probably still be a thing it was possible to do, but riskier than now, and much riskier than the rest of the kit of the reworked infiltrator (which I've been calling "Instigator").
As for the changes...the plan is to have them actually build up networks of (NPC) contacts in areas where they want to operate, who can then bring them information. Then they can place (NPC) Agents who can carry out specific sabotage missions, and may end up getting caught if they haven't been allowed to gather enough information on the target. (Or if they just get unlucky.)
Then if they're loyal enough to you, they die before revealing your name. Otherwise you may end up with a ban...but since you haven't had to actually be there since you started building your contact network, that's not nearly as much of a danger as it would be under the current system. If they want to find and eliminate all your Agents, they'll have to engage in some harsh policing practices, and it's nearly impossible to root out all your Contacts in a city of any size.