Level
6th
Casting Time
1 Action
Range/Area
Self
(60 ft. )
Components
V, S, M *
Duration
Concentration
1 Minute
School
Evocation
Attack/Save
CON Save
Damage/Effect
Radiant
You launch a sunbeam in a 5-foot-wide, 60-foot-long Line. Each creature in the Line makes a Constitution saving throw. On a failed save, a creature takes 6d8 Radiant damage and has the Blinded condition until the start of your next turn. On a successful save, it takes half as much damage only.
Until the spell ends, you can take a Magic action to create a new Line of radiance.
For the duration, a mote of brilliant radiance shines above you. It sheds Bright Light in a 30-foot radius and Dim Light for an additional 30 feet. This light is sunlight.
* - (a magnifying glass)
They removed the "Undead creatures and Oozes make this roll at disadvantage..."
I'll be honest, I never really understood why oozes in particular had disadvantage when nothing else works that way. Is it meant to represent drying them out or something?
Does this spell cancel the Darkness spell?
no, because it is sunlight.
There's nothing in either this spell's description or the description of Darkness that says it does, so it doesn't.
Quote from the darkness spell you just linked seems to indeed specify.
"If any of this spell’s area overlaps with an area of Bright Light or Dim Light created by a spell of level 2 or lower, that other spell is dispelled."
And from the above description of Sunbeam...
"For the duration, a mote of brilliant radiance shines above you. It sheds Bright Light in a 30-foot radius and Dim Light for an additional 30 feet. "
in older editions, yes, oozes avoided direct sunlight
The question was whether this spell cancels the Darkness spell. The text you've quoted has nothing to do with that; it says that Darkness can cancel 2nd-level or lower magical light spells, not the other way around. Since this spell is not level 2 or lower, it's irrelevant anyway.