I think it makes a lot of sense to make it 16 inserts, especially because of the flexible pre/post fader divider. Gives a lot more flexibility, even if you never use the inserts. Also, just from a marketing standpoint, it wouldn’t make much sense to increase from 8 to 10 or 8 to 12 for example… that seems kind of lame. So why not go all the way to 16 since that’s a nice double of what was there before. “Double the inserts with flexible pre/post fader divider” sounds more impressive. And besides that, computer number schemes often follow the power of 2, so it’s so common for programmers to think in intervals of 2, 4, 8, 16, 32, 64, 128, etc…