All new inventory developments since then have have search functions which allow for far more organization than anything which came before, which literally zero people have complained about. The "we're going to change it to an unsorted mess" claim is simply incorrect. Most of the moaning was from folks who felt they needed to have a MINIMUM of one slot for every named item in the game - who were admittedly using their TR caches as limitless storage, and those who fear change because "spaghetti code" and other buzz terms which do not apply to most situations. We had a shot at having the TR cache issues resolved with this change proposal, and ForumDDO™ blew it so bad the breeze can still be felt today.
What I see here is a lengthening of the grind due to partitioning of character power (how can we know? they already stated it they wanted it to be more gradual), which results in more irritation, which results in (hopefully for the company) more people purchasing their way through the irritating parts - which will of course lead to yet another new grind system being sold to us, with the ability for us to purchase our way through that as well.
Add on top of this that they already stated they would like to address lag issues before merging servers, but we see no such concern about addressing lag issues before dividing the player base up even more than it already is, which means more instances, more players resorting to crushing lower difficulties where red-alerting-on-purpose is survivable (and even encouraged given the AOE nature of DDO) rather than dealing with the tedium of slogging through high mob HP totals with less character power, etc...
How do we know? Pattern recognition since 2009. Its on them to break the pattern. Its not on us to believe or assume anything different will occur.
If they wanted character power acquisition to be more gradual they would change the level 27-29 gap before anything happened with destinies. This isn't for game balance, its for selling mitigation of time consumption.