Thanks mendy7511, pitz, YYC009 and krayZpaving, that's very helpful and gives me some comfort level.
If I use miles to book this, can I still select the seat (by paying extra of course)?
So while the USD 100 seat fee will be gone (I guess that's non-refundable like with SQ?), at least this way I am not fully committed (just in case of random equipment change).