TPIR has a question mark on them because new episodes are known to have been aired during the summer months.
TPIR: June 20 (?) (according to priceisright.com)
Did you even look at the page you cited?
PIR.com's calendar lists the airdates for every new show this season. It clearly shows some skipped episodes airing over the summer, and it clearly has a new episode on June 21.
For anyone who cares: The shows on June 24 and 25 were pre-empted in December; the show on June 28 was pre-empted in February; July 4 is the actual season finale; and July 17 was shuffled off the day after Christmas so they could plug in the first responders episode, which actually comes right before the July 4 show.
"When is TPIR's season finale" can have different answers depending on how nerdy you want to get, but "June 20" is obviously not one of them.