This is really a question for an elder law attorney but roughly-speaking, what that means is:
Americans who cannot private-pay for their care can receive government-funded care in a nursing home. The government will start making payments only after the senior has exhausted their own assets, including cash assets (bank accounts, stocks, bonds, etc), real assets (houses) and other large assets (cars, boats, etc). The senior can't just say "I wish to leave my house to my children therefore the taxpayers will pay for my nursing home". And there is typically a 5-year lookback period to ensure the senior doesn't shift assets to their children as soon as they need to go to a nursing home.
One exception is the primary home, where there are two scenarios. Scenario one, when one spouse goes to a nursing home but the other spouse does not, the government will let the other spouse remain in the couple's shared home, and furthermore will let that spouse keep half the assets so a couple doesn't end up spending all of their savings on whomever gets sick first and leave the other spouse destitute. Scenario two, if a senior is temporarily disabled (as determined by social services and medical professionals) and "plans" to return to their home, the government will not force them to sell their primary home to pay for this temporary care so the senior is not homeless after their temporary hospital and/or rehab stay.
Now, the terms "desires to return to their home" and "plans to return to their home" are a bit of an industry euphemism. Nobody ever chooses a nursing home over their own home as a matter of preference. There exist some very upscale assisted livings (that are more like a fancy cruise ship than a senior home) and sometimes wealthy seniors choose to live in them as a matter of preference but literally nobody ever in the history of humankind had chosen to live in a nursing home. Children or social services have to drag their elderly parents into a nursing home (metaphorically) kicking and screaming after all other options (home care, physical and occupational therapy, in-home disability modifications) have been exhausted. The euphemism exists because those who work in the senior care industry, and the social services industry in general, try to be respectful of their clients even if these clients are poor and elderly.
In your specific case, since there are multiple properties including secondary residence(s), I would recommend contacting an elder law attorney specializing in your area (your state and your county).
(My bona fides: I own a company specializing in eldercare placements.)