I've pulled up some old linoleum flooring that covers a slab and basement in a horseshoe shape around interior wall where the division is split 50/50. Between the 2 foundations is approximately a 3/16" gap.
The basement edge is about 1/8" lower max where the foundations meet and a has a 3/16" subfloor material over the std particle board. The slab side has a thick, smooth plywood surface.
Would an expansion joint of some type be preferred when planning a tiling for this application?
Not only is it preferred, but it's mandatory. Somthing like that can't even be bridged so the expansion joint can be moved to a grout joint. Right where that joint is, must be honored with an expansion joint that goes all the way through to the tile's surface. If you can lay the tile out so as to have that land on a grout joint, great. But if not-- if it would cause slivers all over the place, or if it's not square to the tile, then your best bet would be to cut it in and caulk it.