Eh. 5e's system is pretty flexible on party composition. As long as you have someone who can Healing Word, someone who can be frontline, and someone magic-y, you're fine. Bonus for having thieves' tools proficiency I suppose, but you can always brute force or get Knock.
There are vastly fewer debilitating effects in 5e that require a Cleric (e.g., Pathfinder's permanently blind/crazy and ability score damage/drain). Healing conscious party members is practically useless, further reducing the need for a Cleric. Anyone can get proficiency in thieves' tools through backgrounds, or training in-game, so a rogue isn't required.
See, people keep saying this, and initially I myself bought into it, but now that I have had the chance to actually play 5e myself, through a lot of Solasta but also a lot of virtual-TT play of 5e, I strongly disagree with this. At a minimum you MUST have a dedicated healer with lots of healing or else you stand to have most if not all of your (small 4-person) party go down during a battle. And rests don't help with respect to keeping your party alive DURING a battle.
