Or, do the opposite, and force everyone to publish (not privately share!) their pricing strategy well ahead of time, but prohibit including competitors' prices

Or, do the opposite, and force everyone to publish (not privately share!) their pricing strategy well ahead of time, but prohibit including competitors' prices or proxies thereof as decision variables. The most resilient strategy possible is the one that works even when everyone else knows and everyone else also publishes theirs but still engages in competition.