The time-line of the submarine attack is off. A submarine at operating depth can only receive ELF (extremely low frequency) radio messages. Due to ELF'S limited bandwidth, information can only be transmitted very slowly this way, on the order of a few characters per minute. The sub would therefore only get a pre-arranged code of a few letters, instructing it to rise to a shallower depth where they can receive the actual message by a quicker means. Surfacing in itself is not a task accomplished quickly by modern subs as they are optimized to stay submerged for most of the patrol. Also, it always causes hull expansion noise which the Chinese carrier group could detect. To avoid that, the sub would first have to move out of range, then afterwards dive again and re-acquire the carrier at torpedo range. All of this can not be accomplished in a few minutes, it would take at least an hour or more.