Please check out our blog starting back from January 2019 and read the posts that describe the fundamentals about how our network functions. We don’t get to spend any part your held amount, unless your node leaves the network unexpectedly and we need to use that held back amount to pay for repairing the lost pieces no longer available from your node. Until then, it is set aside and half will be paid out to you after your node has been online long enough, and the rest if you choose to gracefully exit. Again, this is all described in detail in our blog posts. I would urge you to not jump to conclusions.
SNOs joined the network at different times, so there is no danger of a sudden flood of tokens being dumped on the market at one time, as not everyone will get their held back amount back at the same time, nor will they necessarily all choose to immediately sell the tokens.