According to the article a Norman Foster design was part of the proposed implementation of the upgrade of the Lincoln Center campus,
The goal is "to improve the hall’s lackluster acoustics, replace outdated patron amenities and reconfigure the auditorium," and "[t]he Philharmonic also now feels a sense of urgency. Many orchestras have folded in the past 10 years while patrons have moved away from season-long subscriptions in favor of single ticket sales," and to create a space that can accommodate various configurations — including a thrust stage, a proscenium or a theater in the round — and to create an environment that honors the conventions of a concert hall even as it expands on them."
I may have missed it, but I'm not hearing a lot of clamoring from long-time audiences and major donors, who are generally older and more conservative, for innovation. (More Ladies' rest rooms and an affordable restaurant, perhaps.) It's not that they might not love it after it's built, but how do you raise money for something that benefits younger and/or less -conservative viewers without deep pockets?
The article mentions an auditorium naming opportunity, because Avery Fisher's family would sue if they tried to change the buildings' name, but within the next few years, some legal mind might be able to squash that. De-coupled from the Lincoln Center reno, it would give a lot of publicity to major donors. (It's frightening to think about who needs that kind of rehabilitation, and it's not Bono's cup of tea to get his fans to fork up millions for this kind of project, although it would be were Paul McCartney to write a big check and have the concert hall named after him [or Madonna].)
When San Francisco Ballet had to move out of War Memorial for the seismic renos, they performed mostly smaller chamber works in less-than-1000-seat auditoriums, except for "Swan Lake" (and maybe the mid-reno "Nutcracker"), which they performed at Zellerbach in Berkeley. Not that they didn't do mixed rep at the time in the larger house, it was not what their audiences were used to, especially in those venues. The Philharmonic could have the opportunity to perform during temporary exile in spaces and in rep that will reflect the new space, and could develop new audiences who might be willing to migrate to Lincoln Center, if there were options apart from a big, formal hall.
They may have to break the orchestra up and perform rep for smaller sub-groups. There is no shortage of smaller performing arts venues in the tri-state area -- think of colleges alone -- and maybe the NY Phil and the NJ Symphony can do a swap for at least a few performances, where the NY Phil played in Newark, then NJ Symphony can play in the new hall when it opens. Hartford is usually left out of the mix, and that's within a long commuting distance.
The union negotiations are going to be interesting.