The WGA strike does not mean no scripted work can film; it means writers specifically are not working, but the rest of the production can continue if the studio orders it to move forward and if the location is not picketed.

Per the article linked in the tweet: the scripts have already been written, there are no writers on set and no more revisions, and Disney has issued a memo forcing the productions to go on and forcing hyphenate WGA members to return to work to do obligated non-writer duties (directing, acting, producing, etc.)—even if it potentially means that forcing hyphenates to do their obligated non-writing responsibilities skews close to or can be interpreted as performing struck work or scabbing.

Andor, like many scripted series filming in the UK that already have their scripts completed, is being ordered to go ahead and film specifically because the studios know that these locations are not picketed like US locations in LA and New York. The majority of the industry is not on strike, actually, and they are obligated to keep working if there is no picket line blocking entry. (Sidenote, late night was suspended because late night scripts are written very close to filming; they must immediately shut down because they have no scripts completed and writer-actors cannot write their own lines. Further sidenote, I do not know where the article got "most productions shut down in solidarity" because that's not really true.)

Until there is a picket line denying entry to the UK studios and locations where Andor is filming, the production of Andor is obligated to continue on without its writers if Disney orders it to do so.

There's something much worse going on here than "the people who created Andor are ignoring the strike and going ahead anyway." It's Disney the studio knows that the scripts are completed and is ordering the production to go ahead without on-set writers, and Disney knows what a hyphenate like a showrunner is and is not obligated to perform during the strike (yes producing, no writing) and is trying to pressure hyphenates like Gilroy to perform non-writing portions of their jobs in a way that may corner them into strikebreaking and get them in trouble with the guild.

Andor (and many other scripted series) that have completed scripts going ahead and filming without writers on set and without any further revisions that may arise as necessary isn't necessarily thumbing their noses at the strike and the WGA, it's working under the strains of capitalism and under pressure from companies to keep working.

The takeaway here is: the studios can order forward productions that have completed scripts and film them and this is perfectly allowed per the WGA strike rules, and the way to halt them is for people in the UK and other local locations to picket them.