The likelihood of the PLAN releasing night-op footage is probably low. Think about why they released the footage that they did... because it looks good. It looks great on state television, it looks cool and motivates the populace to contribute to building a strong navy. Do night-ops look good on TV? Perhaps, but not likely; it's dark and so many details are obscured. It contributes little to looking cool on TV. The only thing it'll achieve is to satiate us military enthusiasts and we constitute a tiny portion of the population. It's simply not worth broadcasting night-ops, which takes up precious minutes of airtime on state television, to satisfy a tiny portion of the audience.
With all due respect, I think you guys are making excuses for PLAN having not done night-op or releasing night-op footage just yet. In all likelihood, PLAN has not accomplished the night-op yet or at least they have not been arrived at the stage where they feel comfortable to release the footage yet.
For anyone who has been closely followed and watched PLAN's carrier programs, it's obvious that they've been pretty open and provided regular updates of progress in carrier development and operations. These include the regular press by MOND spokesman, regular footage releases via China's national television programs on the key activities and milestones of Liaoning, interviews with key personnel involved in the construction and operations of carriers, etc. I don't recall any other defense programs that have received such broad, regular and consistent attention and coverage in China (J-20 would be a distant second). This is not surprising. No other military program has the same visual appeal, the scope and complexity of the operations that arouse the pride of the nation.
Carrier night-op is very complex and dangerous; successfully mastering it would represent another milestone in PLAN's carrier operations development. The visual image and footage would also be difficult to resist for the general public. As such, it's hard to imagine that PLAN would hide or let go such a great PR opportunity.
The only reasonable explanation for them not having released such footage is that they're not ready yet and have not felt comfortable doing so. I'm sure they've been practicing night-op at least in some limited fashion. They'll release them when it's the right time.