Do T5 Graveyard Map bosses respawn?

Do the bosses from T5 Graveyard map respawn after you defeat them?

After dying 4 times to them (rain of arrows gets me every time) I thought I had it beat only for them to respawn. Playing SSF R and it was punishing losing 60% of my XP. I couldn't find any videos to check the mechanics.

Graveyard has 3 bosses (by default, I'm not sure if it can roll the "twinned" affix that doubles them or not).

They spawn sort of "in the round" so to speak.

First boss A spawns. You kill him.

Then boss A and boss B spawn. You kill them both.

Then bosses A, B, and C spawn. You kill them all. Now you're done.

Note there are "adds" of regular undead mobs in addition to the bosses.