S&D as in the definition of the word search and destroy can be done in default maps. You either cap a spot atm or destroy something. Even stock maps in RO have mapobjectives you often need to blow up with a satchel.
Although thats not the case of issue here.
One thing is though that although battles werent fought in empty places, loads of people like a gamemode with limited lives because it makes a person have a lot more care for their one life. Generally people call a gamemode with 1 life generally search an destroy (even if you cap something rather than blow it up), its the general basic gamemode of counterstrike, medal of honour and cod, and loads of gamers love it.
Personally rather than 1 or 2 objectives with 1 set of lives, i would like to see it as a variation of a gamemode. Normally if your team died or obtained the 1 or 2 objectives you change map.
What if you just play on another section of the map when you obtain 1/2 capzones or your squad dies. Like advance to the next set of capzones.
That way 1 map is like multiple S&D maps combined (think of an S&D campaign that connects seamlessly), with this no new base maps need to be made saving some development time primarily changed objective order and flow. While pleasing the crowd that loves low player amount gameplay.
It wouldnt be the gametype i would play, but in the non ro division of icm most people that stopped with ro stopped because they didnt like the fast respawning coming from a 1 life round scenario.
I dont think it will split the community too much personally, as it will primarily cather to a crowd that is pretty much completely abundant from the ro universe at the moment. Although generally realism units seem to prefer this type of gameplay as well.
The reason of importance of including such a gamemode officially preferably in the first release is simply, that if such a game mode is there, the lovers of that style of play will know it offers it at release. Creating a community for that gameplay style right away. If its added through a mod or later in release, then a big amount of the possible community that could be gained is missed.