Will newer bags eventually replace the Andiamo on social media? Absolutely. Brands and influencers will alway push newer styles to the forefront of our minds. This is by design.
Will the Andiamo eventually be discontinued? More than likely, but I think it will remain popular for another year or two. It's also quite possible it will be revived later, just at the Knot and Lauren were. In the few years I've followed Bottega Veneta, I've never seen a style that is a consistent house staple, such as a Chanel Classic Flap or an Hermes Birkin. All styles seem to disappear from the boutiques eventually. I think Bottega will always have a hobo in their lineup - that seems to be their classic silhouette.
Perhaps most important - Is the Andiamo classic in style and wearable for years to come? I'd say so - especially in a neutral color. I own many Bottega Veneta bags for this reason. Some of my bags are almost 20 years old, but they look just as beautiful now as they did when they were introduced.
If the Andiamo style works well for your lifestyle, then I think it could be a bag you enjoy for many years. Good luck with your decision!