Thus, in the Spring of 2017, just as The New York Times began a publicity blitz that touted its commitment to the truth ("Truth: it needs your support") and that would greatly boost its number of online subscriptions, it headhunted Bret Stephens, a climate-denialist op-eel writer, from The Wall Street Journal - all in the name of editorial 'balance" (presumably between facts and non-facts).
The word "blitz" is used glibly to describe an intensive campaign. It refers to "the Blitz", which was a heavy bombing campaign during World War II. The word is German for "lightning" and so when used in a modern sense, speed is implied as well as intensity - a lot of work condensed into a short period of time. For example in British English "blitzing the kitchen" could mean cleaning the kitchen very quickly but thoroughly.
A "publicity blitz" would be an intensive publicity campaign.