As an AI language model, I don't have access to real-time information or specific release dates. However, I can provide you with some general information about offline conversion tracking and its potential updates.

While I cannot provide you with the exact release date of a new offline conversion switch, it's worth noting that major advertising platforms like Google Ads and Facebook Ads regularly update their features and tools to enhance advertisers' capabilities. These updates often include improvements to offline conversion tracking.

To stay up to date with the latest developments, it is recommended to regularly check the official documentation and announcements from the advertising platforms you are interested in. These platforms usually provide release notes and updates on their websites or through their official blogs.

When writing your article, you can cover the following points to provide a comprehensive overview of offline conversion tracking:

1. Introduction to offline conversion tracking: Explain the concept and importance of tracking offline conversions in online advertising campaigns.

2. Benefits of offline conversion tracking: Discuss the advantages that businesses can gain by tracking offline conversions, such as better ROI measurement, improved campaign optimization, and enhanced customer insights.

3. Existing offline conversion tracking methods: Explain the current methods used for tracking offline conversions, such as unique identifiers, coupon codes, call tracking, and CRM integration.

4. Limitations and challenges: Discuss the challenges faced when tracking offline conversions, including privacy concerns, data accuracy, and technical implementation difficulties.

5. Recent updates and improvements: Provide an overview of recent updates or improvements made to offline conversion tracking by major advertising platforms. Include any information you can find about the new offline conversion switch you mentioned.

6. Best practices for implementing offline conversion tracking: Offer practical tips and recommendations for businesses looking to implement offline conversion tracking effectively. This can include setting up proper tracking mechanisms, aligning online and offline data, and utilizing attribution models.

7. Case studies and success stories: Share real-world examples of businesses that have successfully implemented offline conversion tracking and achieved positive results.

Remember to conduct thorough research and cite credible sources to support your article. Additionally, keep in mind that the information provided here is based on general knowledge and may not reflect the most recent updates or developments in offline conversion tracking.