possible if SMRT want to have the seats that way.
but don u think its kinda awkward? xD
Nope, it's rather common in other countries. No need to go far,
Malaysia's KTM Komuter have some trainsets that have this kind of
seating configurations.

Configuration is [DOOR] <side-facing> <forward>
<backward> <side-facing> <forward>
<backward> <side-facing>[DOOR]
Of course, with the "Please move in to the centre of the car"
thing, it's impossible to have this in the centre of the car. So,
since the gangway is already narrow, the forward/backward* facing
seats won't affect the flow of passengers too much.
*To avoid confusion, the seating direction depends on the
direction of travel of the train. It is just 1 pair of seats, not 2
pairs leaning against each other. Hence, only the layout is changed
and not the total number of seats.