Information exonerating the Templars has been held in the Vatican archives, for 700 years. It wasn't lost, it was held in secrecy.
And, to what purpose? Secrecy seems to have been creating problems for the Vatican, regarding controversial matters within the hierarchy, for a very long time. It's certainly not a recent development.
I continue to admire the Templars, because they were founded by men who were willing to give up worldly wealth and pleasure in order to serve Christ and his disciples.