I don't know, somewhere along the way it feel the message in this thread, outside of the thread title itself, turned from a reasonable in my opinion message of 'hey, now that WOTC has backed down somewhat and 3PPs can keep publishing for 3e / 5e, don't forget to try and support 3PPs, given our push back was based on 3PPs being hurt' to something more like 'purchasing official WOTC products is the only way to support 3PPs, any other way is going to hurt them and you should feel bad about it' - feels like some form of emotional blackmail pushing an obligation on us to buy WOTC products, when there should never be an obligation for consumers to buy a product from a provider, if there is an obligation it is an obligation on the provider to provide a product people want to get.
If people have lost desire to buy from WOTC as a result of what has occurred - that is on WOTC ultimately, if there is some sort of moral obligation to make sure 3PP aren't hurt, then I would argue WOTC should be the one making it right, not consumers.
If 5e shrinks as a result of this, then ultimately the 3PP will need to change as a result - not necessarily fair on them, but unfortunately it happens, as in any industry if the market moves for whatever reason - plenty of businesses close down every day sadly, but that isn't consumer's fault for that occurring - things just change. Just be glad that thanks to WOTC backing down in the face of consumer pressure, that 3PPs are able to publish as freely as they are able to, even if to a smaller audience - it is far better than what the alternative would have been.