The FAQ asserts that the academy is not excluding older members.
Everyone will retain membership.
It goes on to detail how academy members who work actively in motion pictures will maintain their voting rights.

Credit: Chris Pizzello/Invision/AP
Three 10-year terms will grant lifetime voting rights, as will winning or being nominated for an Oscar.
The same standards will be retroactively applied to current members.
Emeritus members who become active again will be eligible to have their voting rights reinstated.
There are a number of academy members, however, who had brief careers and left the business.
We want to strengthen, uphold, and maintain the credibility of the Oscars with these new criteria.
Voting for the Oscars is a privilege of membership, not a right.