We just replaced the unpronounceable initialism DSLR with a pronounceable acronym MILC and an even more pronounceable word "mirrorless" and you want to take a step backwards to another initialism that has to be spelled out?
That aside...
Instead of the wacky "mirrorless"?
Mirrorless sounds like "horseless" ... "horseless carriage."
SLR stands for single lens reflex (mirror).
DSLR stands for Digital SLR.
So DSL stands for Digital Single Lens. (no reflex.)
No. DSLNR stands for "Digital Single Lens. (no reflex.)"
DSL stands for "digital single lens", which includes DSLR.
And you've still embedded the concept of it being "without" something into your definition.
Seriously, the only thing that makes sense is to incorporate the words interchangeable lens and electronic viewfinder. Whether you choose an English EVIL or a French LIVE is up to you. The swap is always implied, like the ISO is simultaneously the International Standards Organization, the International Organization for Standardization, and the Organisation internationale de normalisation.
Although I have to admit that ECCO "Electronic Composing, Changeable Objective" has a certain charm. Ecco Domani!