Releasing products on a set date is a tradition. Catalog's are an advertising product. This tradition most likely stems from good businesses practice. IMHO its creates anticipation which is good for advertising, it's orderly which probably makes it cost effective and it's fair (consumers have equal opportunity to get a catalog and dealers don't get a run on catalogs).
Tradition? Maybe the NEW tradition is releasing the catalog, then coming down on forum providers for publishing the information before it goes online... Before there was an internet, there were always whispers of the next catalog.
I didn't see people falling over themselves at the catalog rack snatching 2019 V2 catalogs at my LHS. In fact, one of the employee's had to point the catalogs out to us. There were still plenty left at closing.
It's a model train catalog forPete'ssake, not the nuclear launch codes. Coming down on people for posting images and information two weeks early makes about as much sense as the dismal running "Paul Bunyan" skit(?) on the one Dave & Ryan show.
Besides, two weeks after the catalog goes online, the buzz pretty much drops off.
If Lionel want to keep it a secret, ship the catalogs on the Thursday or Friday before it goes live online. People are still going to praise or criticize the contents and/or pricing regardless on when the information becomes public.
Lionel may get an additional two weeks of buzz, but minds are probably not going to change between hard copy leaks and online publication.