That is a whole mess of giant neon red flags that something is wrong here regarding engineering for resilience and trusting your deployment system to catch errors.
Additionally, for a freeze lasting weeks, unfreezing and resuming merges from some backlog of frozen changes would likely introduce far greater risk to revenue or to customers than managing a trustworthy deployment workflow during high traffic events. I would even question the fundamental premise that this is safer or beneficial to customers at all. It seems much, much more likely to be a “cover your ass” method to prevent any possible blowback from outages due to unremediated tech debt that the weak leadership is not capable of protecting as a worthwhile priority for quarterly goals.
If so, that's very impressive, but also very atypical. Source: I work in high-volume ecommerce, have friends and colleagues at other companies who do likewise, and no one I've talked to about it works anywhere that doesn't implement at least some controls on at least checkout-path deployments during holiday prep and through holiday proper. It isn't a tech debt thing, it's just good business sense: the time of year when people give you by far the most money is the time of year when you least want to risk causing problems for people who want to do so. The problem isn't untrustworthy systems or bad engineering culture; the problem is that anything short of perfection has a measurable impact on revenue, and humans achieve perfection with less than perfect reliability.
Even where I work, that revenue impact can easily amount to a major problem if we let a significant bug slip through. People buy our product for its own sake, and will do so from Amazon or Walmart or wherever if they can't get it direct - but our margin on sales through second-party vendors is nothing like as good as on direct sales, so we still take a hit. For Etsy, it's much worse; on sales through other storefronts, they get nothing. Too, a bad enough break during holiday will also risk some fraction of their subscriber revenue from sellers who, fed up at losing out on what would otherwise also be their highest revenue of the year, might go elsewhere.
It's easy to talk shit about tech debt and bad engineering culture, I get that. It's also poorly founded in fact, and evinces an apparently questionable grasp on some fundamentals of the business, besides. I don't know whether you have represented yourself well or poorly by creating this impression, but it is the impression you've created, and if that bothers you then I might suggest trying to do otherwise next time.