Looking on linked in the two that resigned Mr Gil Don had been with the company for 11 years. Maybe he’s ready for his next adventure. Possibly they were looking for a successor to replace him for a while?
https://www.linkedin.com/in/gil-don-0744907
The other person who resigned Mr Michael DeFranco had only been with the company a year and looks like he has a few other jobs at other companies. Not really sure why he was on the board?
https://www.linkedin.com/in/michael-keoni-defranco-25b2ab17
As for the two people promoted to board Brad Paterson has quickly advanced within the company in the past 8 months. - read the recommendations given by others.
https://www.linkedin.com/in/bradpaterson
The new person Mr Jan Koelble seems much more suited to be on the board then Mr. Michael DeFranco.
https://www.linkedin.com/in/jan-oliver-koelble-66940a22