I read the information in the same way as gene134.

I've noticed, from checking the LX schedule later in the year, that the A333 flights from JFK-ZRH seemed to be fixed to one flight number - LX15 - rather than swapping beteen LX15 and LX17 on certain days. This fits in with the LX press release on 20 April which mentions the A333 will operate on flights LX14/15. As usual, YMMV.