oil level on 1994 Buick Park Avenue

Rookie cbe0621eac06868b3efe0d8d1d3611e23c60d3114864ea2ec19a68cfbd3eebab
resently had an oil change
now engine blown up
they say oil level sensor un plugged.
would i have seen bells and whistles?
maint.every 1500-2000 miles
(2) Answers
first of all, why did the engine blow up? was it lack of oil, timing chain failure or other? if something was done wrong at the oil change, whatever happened would have been right away. Any more info would be helpfull.

lack of oil not in the sense no oil
had to have some oil or you are right
would have blown up sooner as long as oil
can be picked up by the oil pump
it will have some oil pumped to the bearings
crank cam bearings ect.