Thinking about this operation a bit, it must be presenting huge implications to the Chinese with respect to Taiwan.
For instance, the power and simultaneity of the joint force attack is pretty staggering. Those initial fires included ground launched ATACMs missiles; air, ground, and sea launched cruise missiles; precision airstrikes using HARM anti-radar munitions and JDAMS; cyber attacks; and undetectable strategic bomber sorties flying 38-hour round trip missions from the American heartland (something no other nation has the remotest capability of doing). That is scaling the initial blow to thousands of simultaneously struck targets. That sort of scale not only reflects on the quality of the hardware, but perhaps more directly on the professionalism of the entire joint force from command planning, through execution, to support and fielding. This and the observation below also casts significant doubt about the quality and effectiveness of Russian and Chinese air defense capabilities and doctrine.
Second, would be the utter ruthlessness of the attack. In the opening minutes the presiding leadership of both the nation and its armed forces was killed. The most newsworthy was the strike which hit the leadership meeting in Tehran, but at the same time headquarters and command and control centers all across the Iranian defense structure were also hit. The Chinese leadership has to realize that those same assets could be carrying out the same sorts of conventional missions virtually anywhere in China.
Third, the intelligence preparation of the battlefield is better than anything I have yet seen. Most importantly, it seems to be extremely timely. One of the major criticisms to which I can personally testify was the lack of timeliness of national and theater-level intelligence during the Gulf War and much of the more recent Afghan and Iraqi conflicts. The US seems to have finally broken the intel parochialism, particularly strategic, that delayed so much critical targeting information in the past.
Fourth, the US seems to have total control over the cyber and non-hardwire communications network. To the extent the Iranian Aerospace forces had any ability to exercise current targeting, that was destroyed in the opening sorties. An Iranian hypersonic missile with terminal guidance might seem a real threat to something like an aircraft carrier, but without the ability to target transient targets in real time, that asset becomes simply another target waiting on the ground to be destroyed.
Fifth, underground facilities sound impressive. But with the right munitions and delivery mechanisms, they suddenly are nothing more than highly vulnerable and easily identified fixed targets. According to CENTCOM, Iranian missile launches are down 90% from the opening day or two of the conflict. That is because Iranian missile stockpiles are being hugely attritted inside their caves. China can be assured similar targeting is being updated daily of its storage locations.
For both nations, the challenge represented by cheap attack drones needs to solved. The US used them for the first time during this campaign against fixed soft targets like radars, air defense sites, and naval assets. An interceptor like THAAD or Patriot can easily engage them, but it is an unsustainable trade ratio. Instead, both area and point defense solutions need to be fielded quickly. The navy is currently operating a laser equipped destroyer with the Ford battle group. Other energy related solutions are being tested by the USMC and Army. One would assume the Chinese are doing the same.
Finally, this challenge is likely only get worse for the Chinese. The first US Army hypersonic units have already been deployed in PACOM (that is now open source) and will soon be a permanent asset. The B-21 Raider will soon go into full rate production, and instead of having 19 stealth strategic bombers, the US will have 100 or more. The F-35 will continue its fielding across the joint force and the F-47 is on the horizon. China must also decide what to do about US bases in Japan, the Philippines, the Indian Ocean, and likely Australia. They can not hope to be successful in taking Taiwan if the US Air Force and Navy have regional sanctuaries that can not be interdicted. This has not been a particularly successful effort by Iran. Japan, especially, can be counted upon to vigorously defend its sovereignty - I wish I felt the same way about Australia.