So I've been planning an upcoming mini-rtw booking and have been noting down how far in advance award seats from different airlines are released to Aeroplan (based on searched done on Aeroplan site).

I thought this might be useful for others as well, as I haven't seen this info posted elsewhere on this forum (I may have missed it.)

Also, these are just data from my own research, may not be 100% accurate. Feel free to correct me if I'm mistaken about any of these.

BR : 355 days
CA: 355 days
AC: 355 days
OZ: 342 days
NH: 330 days
TG: 340 days
SQ: 350 days
LH: 350 days - F release at ~T-14, J unknown.
LX: 339 days
OS: 355 days
UA: 330 days
TK: 355 days
LO: 355 days

To clarify, these dates are just "typical" dates, as in the first date you should expect to start seeing award availability from a specific airline (not specific to Y/J/F - I've seen on occasion F being released on day 1, but no J/Y etc.).
To my knowledge, only LH withholds J/F until closer to departure.

This does not necessarily mean that you'll find award space right on those dates though. Airlines release award seats at their discretion, and additional seats my be released closer to departure date.