As has probably been hammered home enough by now, basically anything Epic's previous tool, which is kept for legacy purposes, could do, Sequencer can also do. That said, there can arise situations where someone has a great deal of experience with Matinee, or maybe an outsourcing group still uses it, and they want to quickly bring that to bear on a project. Other than the already-stated reasons of Sequencer being the supported tool going forward, there's not a specific reason Matinee can't be used still. Matinee has been a classic for having flying cars loop around buildings in smooth parabolic curved circuits. It was the mainstay of cinematic work in any number of classic UE3 and all early UE4 titles. Anyone having just gone through the Sequencer work should immediately recognize a lot of familiar themes opening up the Matinee editor:
While the main striking difference is the curve-editing tools on the front face of Matinee, fear not, all these controls and some new perks are available in Sequencer (check out the tool button near the top of sequencer to view as a curve, and select a transform or other track with keyframes):
Regardless of what ultimately works best, knowing the options available is the name of the game in making your project a success, and in all likelihood, you'll end up using any number of the options available in some combination; but by now at least the risks and possibilities should be clear from the start.