I feel it depends on how one wants to categorize "weak" from their perspective. I guess you can say they are "weaker" in terms of the variety of AD missiles compared to US DDGs/CGs, but again, you have to look at the operational contexts. Some of those aren't needed, at least not now. Using the examples of US SAMs you listed:
SM-2 = PLAN SM-2 equivalent is basically HHQ-16, which is on their FFGs (especially newer FFGs, which should be using the 160km HQ-16F); they don't need this on DDGs when HHQ-9B exists.
SM-6 = HHQ-9B is essentially equivalent to SM-6 in terms of role and functions, but likely worse in BMD
SM-3 = BMD again is not a priority for the PLAN as they face no mass ballistic missile threat. Of their BM threats (which are mostly ICBMs), that is taken care of by land-based systems. Any future BMD missile that embarks on PLAN DDGs will likely have been developed to deal with maneuvering hypersonic threats (HGVs, HCMs?) that some adversary country has fielded, but can of course shoot down other regular ballistic missiles
quadpacked ESSM = this has been debated before, and I believe will come eventually, but must not be seen as a major priority, as maybe they deem they don't currently face any major threat of swarm attacks?, or are pushing for something more capable than just some ESSM equivalent
There is this though that was seen, which looks like a SAM rather than some anti-ship/land attack missile. My guess is it kind of looks like a naval version of HQ-9C? Which would probably be a better equivalent match for SM-6 than HHQ-9B, specifically in BMD as HQ-9C is tailored more for BMD, but likely with even more range than HHQ-9B as it clearly has a booster section. Doesn't look like it would replace it, but rather exist alongside it, and be used more for BMD (maybe optimized against hypersonic threats as well (?)) and as a longer-range, anti-air SAM to hit further distant targets cued by AEW&C aircraft. But I could be wrong, we'll wait and see what it is as we get closer.
