It's not forced movement, but per the Player's Handbook errata, trying to teleport creatures into dangerous terrain or to a spot where they will fall gives them an immediate saving throw to avoid the teleport.
Teleportation
Page 286: Replace the text for the Destination entry
and the Immobilized entry. This change addresses
what happens when a creature is forced to teleport,
and it clarifies that the Immobilized entry includes
restrained as well.
✦ Destination: Your destination must be a space you
can occupy without squeezing. If arriving in the
destination space would cause the target to fall or if
that space is hindering terrain, the target can make a
saving throw. On a save, the teleportation is negated.