If I am reading the article correctly, it does NOT say the contamination is gone but that the local business owners talked the local gov't into removing the signs because they were impacting business. Is this a correct interpretation or has my fledgling Spanish gone awry?

No, locals went and removed the sign themselves and replaced it with the one in the photo I posted above.

The fact is that even though locally we all avoid swimming at Playa Principal, there is no reliable or professional testing taking place and thus it makes no sense to simply leave warning signs up week after week since conditions change daily and no testing is done weekly as it is done along the more popular public beaches in Florida and California. The signs were hurting local businesses, and since the government is NOT taking a professional approach to the matter I have to say I am not entirely displeased with my friends, family and neighbors for taking matters into their own hands.

Did they take down the contaminated signs for the puente?

You must've missed the news from a little over a week ago:
CIVILES RETIRAN ADVERTENCIA SANITARIA EN LA PLAYA PRINCIPAL

We're celebrating a long weekend holiday so folks are starting to show up in spite of the negative comments last evening on the national news about Zihuatanejo-Ixtapa, and this morning swimmers were tackling the big waves on the Playa Principal.

Most folks who usually run and walk along the Paseo del Pescador were frustrated from doing so due to the high waves over the walkway and the beaches including La Madera.

Here you can see how high the waves reached in front of the museum on Playa Principal, staring TS Odile right in the eye.