It's always been some kinf of payable release every year as far as I remember - so we all know what to expect. Something happends between sept-dec of new releases.
They skipped the "buy x2 get x3 for free" thingy this time. I looked for that.
I think the best way is to see the discount in summer as your discount for x3. After all Cake's upgrade costs are very reasonable - and I'd like to say generous as well.
Look at Microsoft for a bit. Buying upgrades of windows cost 3-5 times what you pay for OEM version on a new computer. Office, Word or Excel cost something like 40% of new full price every upgrade.