Google is no longer recommending its proposal to make AJAX pages crawlable.
Google continues to recommend against disallowing Googlebot from crawling a site's CSS or JS files and recently updates its technical Webmaster Guidelines to reflect this.
There's really no reason to abandon the AJAX crawling proposal if everything is working fine on your website, but Google does recommend following the principles of progressive enhancement, using the History API pushState(), for example, to ensure accessibility for a wider range of browsers (and Google's own system).
Digital marketing executive with proven experience in all aspects of search engine optimization (SEO), performance-based advertising, consumer-generated/social media, email marketing, lead generation, Web design, usability, and analytics. - 20-year Internet marketing veteran, currently serving as the Digital Marketing Campaign Manager at Antenna Group (formerly Chicago Digital). - Former Editor-In-Chief of Website Magazine, and a regular speaker on Web technology digital marketing strategy - Author of several books on digital marketing Including Web 360: The Fundamentals of Web Success; Affiliate 360: The Fundamentals of Performance Marketing; Domains 360: The Fundamentals of Buying & Selling Domain Names, and SEO 360: The Fundamentals of Search Engine Optimization.