This is extremely similar to the sudden announcement of policies by all the major newspapers that they were not going to publish documents that they thought were stolen by foriegn intelligence services from political campaigns: it is a reasonable position to have, and if announced well before the election season started would be completely unobjectionable. Doing it when they announced it, however, is significantly changing the rules in favor of one candidate.

Doing it after the board had already written up a document endorsing a candidate (demonstrating clearly that it was not a policy of anyone but the owner, who decided to be an utter coward at the last minute) sends a clear message that even one of the richest men in the world is scared of possible backlash against him.