The notion that storylines are changed based on fan reaction is long outdated and anecdotal at best. The execs in charge see what works and what doesnt as they are producing the show. They work within the constraints given to them by dwindling budgets, actor availability, network guidance/interference, and contractual limitations. They scrap ideas and plot developments all the time, which is why we sometimes get a jumble.
Filming so far ahead does have a major negative impact -- mostly because of the rabid fanbases, being so deep in bed with the soap media, and actors spilling info on social media.
Unless Ken Corday's plan is to have a solid year of product in the bank, ready to sell to the highest bidder, they are going to need a major filming hiatus at some point.
ETA: I do think having an inventory is part of Corday's Plan for a post-Sony DOOL. He will have valuable product in the form of a couple hundred hours of un-aired network quality content. He can shop that around to interested parties as we move further and further away from scheduled daily appointment TV.