1. It is confirmed that Mr. Jun Hirakawa, who was (forced) early retired by Hoya back to 2010, is now working for Tamron and below is the evidence:-

The above is a Japanese patent application in 2013 which shows that the inventor of the lens is Jun and the intellectual property owner company is Tamron!
Btw, for those who might not know who Mr. Hirakawa is. He was/is the optical engineer and designer of the FA28/2.8, FA35/2 and FA43 and 77 Limited lenses, FA*24/2, FA*85/1.4, FA*80-200/2.8, as well as the DA10-17 Fisheye, DA14/2.8, DA40/2.8 Limited, DA*55/1.4 and etc. (Amongst those I own nearly half of the above great Pentax lenses myself!)
2. The following quoted picture from the Japanese Pentax forum shows and summarised whereabout of many of those famous ex-Pentax optical and camera engineers. In fact, most of them had left the company and are now employed by the competitor companies like Nikon, Sony and Tamron:-

3. After years of (hard and excellent!) works for the Pentax (Shanghai) China as the marketing manager, Mr. Blurry Cameraphone (Mr. Jopy Yang) has finally left the company. :-( Via a Xitek post in the above thread here.
In fact, his fate is just like Ned Bunnell, it was widely believed by many Pentax users Ned was forced to leave the company one year after Ricoh's takeover. However, the Ricoh-core replacement of Ned is just a pure salesman who knows nothing about Pentax but seriously needed help from Pentaxians, which is utter sad afterall! >:-(
Just a few months before, I actually heard via a third person who were close to Mr. Yang about his disappointment on the latest development of the Pentax line and there was no concrete plan of any for better development of the system. Maybe that was the reason he left the company himself? Or, he was forced to do so??
Old Reference Posts:-
False Rumour - Jun Hirakawa is NOT Back!
The Very Different Fates of Two ex-AOC Top Optical Engineers
Some "Lost Stories" About the Three FA Limited Lenses
Ned Bunnell is (Forced) to Retire so Suddenly and Urgently!
Z.T. · 608 weeks ago
Re Jun Hirakawa, well, if he works for Tamron and Tamron makes lenses for Pentax cameras, then we are still enjoying master Jun's ideas, right? :)
Your last comment about mr Blurry sounds a bit forced but in reality that story means nothing to any user, same as Ned's departure. Sometimes you can accept that some people want to have time with families and retire from corporate culture. They leave jobs to young and energetic ones.
Speaking of that, one day you may also retire from all of this :)
Dan Johnson · 608 weeks ago
Z.T. · 608 weeks ago
Let them be in peace. I think that Pentax needs young and energetic people willing to risk and do bold moves, and I hate to be fed with all the same nonsense over and over again served by those who have no clue about future roadmaps and brand development.
Dan Johnson · 608 weeks ago
Lars Fjellman · 608 weeks ago
Lars
Peter · 608 weeks ago
RiceHigh 110p · 608 weeks ago
Alex · 608 weeks ago
Simon T · 608 weeks ago
Ricoh well they've no talent left, so good luck to Tamron for giving the guy a job. Let's be blunt most K mount users buy Tamron stuff to beef up the bad lens range anyway
But neither Tamron or Sigma are supporting Pentax with some newer lenses, K mount is slowly dying and Ricoh are putting more nails in the coffin with their price hikes