Yeah, there's no logical distinction, only a moral one.
Imagine 3 scenarios:
Company A rolls out a new mandatory update to a phone that addresses a CPU vulnerability, and to compensate for the reduced performance, overclocks the CPU so now your battery life is 20% shorter.
Company B rolls out a new mandatory update to a phone that improves the battery management so phones do not shut down unexpectedly. However, due to lack of hardware battery reporting when the device was built, they could only estimate the capacity based on the phone's age and natural battery degradation. This causes older phones to have 20% shorter battery life, even though some batteries that were not used as hard could have supported longer.
Company C rolls out a new mandatory update to a phone that detects the phones age and reserves 20% battery capacity on older phones, forcing them to have 20% shorter battery life so users are incentivized to upgrade.
The end result is the same, a phone with worse battery life, but we don't see all of them to be morally the same. The only real difference is the human intent behind it, which is why we probably eventually need regulations that make sure companies should justify that they have a reasonably good intent if challenged. Getting this right is very hard -- you don't want to overburden companies from frivolous cases, but you also want regulations to be effective so they can't just handwave them away.