I am struggling to understand the motivation for this question, but I'll take a guess. From the Reddit post you linked, it seems like you're wondering if alternative ways of securing the blockchain will be adopted by companies who have an interest in keeping costs low? I'm not sure exactly what costs you mean here, maybe costs associated with securing the blockchain?
Who really knows? It's possible, but any answer is really just a best guess.
One thing to be noted is that it's not actually companies who build tech around bitcoin that have an incentive to keep blockchain securing costs low. Companies building technology around Bitcoin (and other coins) work almost exactly the same depending on whether the system is secured with PoW/PoS/other, assuming the system meets some base security level. Rather, it's the miners who have an interest in keeping costs low, and fees high. I don't think that mining companies are being invested in as much as companies that are building tech around the bitcoin blockchain.
Is it plausible/possible for corporate interests to divert miners/investors from Bitcoin's blockchain to another blockchain with better rates of return (perhaps just initially) on investment?
What kind of rates of return are you looking for here? If you mean rates of return while mining, then see above paragraph. If you mean rates of return for just using the cryptocurrency, then you probably won't be seeing one that is better than bitcoin any time soon, partially because of bitcoins' spreading adoptance and partially because it is a deflationary currency.
If by rate of return, you essentially mean least costly to transact, then you are talking about the fee structure in bitcoin. One of the problems with bitcoin's current fee system (in the long term) is that the people making the transactions are the only ones paying fees. Or rather, those who are just storing bitcoins are still benefitting from the security while not paying for that security. Inflationary currencies differ in that those who store it pay for the security, in a sense, by the money they have losing value over time.
Coding in a slight inflationary factor might make a currency more appealing to transact with. PoS coins have inflationary factors (as do some PoW coins, this one for example), and from this perspective, I could see companies preferring to store value in Bitcoin but transact in a different currency which has some inflation. So, I could possibly see some companies wanting to invest in other currencies that are cheaper to transact in.