JEDEC standard timings?

JEDEC DDR4 standard has the following 2666Mhz timing defintions:

DDR4-2666T (17-17-17)
DDR4-2666U (18-18-18)
DDR4-2666V (19-19-19)
DDR4-2666W (20-20-20)

Does that mean that all sticks that have different timings from those above are out of spec even if they don't use XMP? For example, is a stick with (16-18-18) timings defined in SPD considered following the JEDEC standard?

Yes if that is the defined spec for jdec on those speeds, then anything outside of that is considered “out of spec”. Almost all ram is run outside of those specifications. Rather done with xmp or manually set.

This is the 2666 table from the spec itself. It's pretty confusing though, it does have different CL settings listed for different "bins". I don't really get how the lower part of the table relates to the "bins".

why are you wondering this? I’m curious.

The only way to find out is by reading the numbers off the chips, but I really doubt many 2666 MHz chips found on modules are faster than CL19.