If you scroll down a little there is

What if you cannot attend? There are plenty of valid reasons why you may be unable to attend a protest or other direct action — but don’t worry! You can still contribute to the safety of your comrades in the streets. Check out the Staying Home Guide for other ways you can show up in solidarity with The Uprising.

I'm with you in sentiment, but is this advice based on experience, or conjecture?

If the former, can you elaborate on your experience with open carrying at protests?

I would extend this outside of protesting if you question your safety in the upcoming years at all. Obviously not open carrying but concealed with a permit if necessary in your state, even California's qualifications are pretty simple and they're usually the more strict of the states. Supreme court already ruled police have 0 obligation to protect you even if you're actively being assaulted and they're ten feet away so I personally will take my safety into my own hands and deal with any potential consequences if I'm ever unfortunate enough to need to use it (CCW insurance isn't a bad idea for legal battles that may follow, don't use USCCA they'll deny coverage for any stupid reasons).

Obviously it's not something every wants to or can do, some people aren't comfortable with the idea and that's totally fine. If you're unsure maybe go to your range and rent one for the day and have them help or a friend help you out and see if you even want to go that route at all. It's absolutely not for everyone.

Some sort of self defense is never a bad idea though and it's usually a ton of fun. Being dangerous both armed and unarmed is great but one is better than none. BJJ, Muay Thai, kickboxing, boxing, anything will set you above most people who do nothing, will even odds against larger adversaries and has a lot of benefits for mobility later in life (hip mobility is huge). You don't have to compete and get in a ring without headgear on to learn to defend yourself, technical sparring is light and usually turns into a fun challenge of reaction time and speed. BJJ competitions are pretty safe all around. Having striking and grappling is never a bad combo because you never know if someone's going to tackle you and nullify your striking ability.

Not everyone is in places where this is a reasonable approach. And not everyone wants to protest peacefully.