According to Time magazine and Gizmodo, 49% share in the patent US2292387 A has been acquired by Wi-Lan in 1998. The patent publication date is 11 Aug 1942, which means it should have expired on 11 Aug 1962. How is such an extension possible?
Such an extension is not possible.
The Time article makes this slightly clearer: (emphasis added)
…in 1998, Wi-LAN bought 49% of Lamarr’s claim to the lapsed patent
A patent can be assigned after expiry. Such an assignment really only assigns the right to sue other parties for infringement that occurred before the patent lapsed.
In this case, I can't really see the value in Wi-LAN's acquisition. Perhaps just marketing?