Yeah ... you could probably get away with just Math::Interval. If the module's description specifies that it performs "interval computations" (as I'm sure it will) then anyone looking for a module to perform interval computations should find it - and should recognise immediately that it does what they want.
The thing I like about "Math::IntervalComputations" is that the name tells you what it does. "Math::Interval" tells you nothing. If it were up to me I'd still go with "Math::IntervalComputations" .... but it's not up to me .... and that's possibly a good thing :-)