Isn't e in starttabulate preamble supposed to make \NC act like \EQ? Try this:
\starttext
\starttabulate[|le|p(3cm)|]
\NC asbcde \NC abcde abcde abcde abcde \NC \NR
\stoptabulate
\starttabulate[|l|p(3cm)|]
\NC asbcde \EQ abcde abcde abcde abcde \NC \NR
\stoptabulate
\stoptext
/S
