Does this policy of not conducting sales transactions apply to all goods and services starting January 15, 2021?
No, the restriction on transacting in the sale of goods and services on WhatsApp only applies to the categories prohibited in the Commerce policy such as health and pharma. If a good or service is allowed to be sold according to the Commerce policy, then it would also be allowed on WhatsApp Business Solutions.
For example, t-shirts are not a restricted item, so they can be purchased using the WhatsApp Business API.
However, all businesses must still comply with the sensitive identifiers policy: Don’t share or ask people to share full length individual payment card numbers, financial account numbers, personal ID card numbers, or other sensitive identifiers.