I believe the only reason why SMRT/TIBS get to operate the
current 825 is because before the amendment, 825 served springleaf,
but after that they amended it to serve only Lentor area. So if
they were to withdraw 825, SMRT may not be able to operate any
basic service from Lentor, Teacher's Estate and Sembawang Hills* as
these are under SBS Transit's territory.
Note: Teacher's Estate and Lentor Premium are Premium servces and
are not subjected to any territorial control.
*This is based on the assumption that AMK extends all the way to
SLE (which is true under URA planning area).