Although  in  theory  it's  the  latest possible version  of  the  Encyclopedia Judaica that's authoritative, it's  not practical to
try  to  enforce this  since  we  all  have  access  to different   editions  (and  printings).   We should  record  the copyright date accurately but not worry about the printing date.   If  someone  discovers  that  a  different  printing  has  a  new  vocalization for  a name,  that  that person should  record the new  form citing the relevant printing date (and make  a  ref  if  needed), but not try  to determine or record the printing date of  the already-recorded differing form.

Encyclopedia Judaica on CD-ROM

In DCM Z1, 670 p. 3 it says:
In citations for publications viewed electronically, either by direct or remote access, give information in subfield $a in the context of the publication rather than how it was viewed; in subfield $b, give location and information.