Hi @Idriss AIT HAFID - This depends on the goal of your 'launch'.
I strongly urge startups I serve to clearly define their objectives from any launch exercise before developing the strategy.
Example 1: Product MVP launch - In this case you are probably looking for validation on whether a product solves a certain problem at all. It's probably fine to launch for free and get adoption, purely with the objective of collecting feedback.
Example 2: GTM research - If you're viewing the launch as a precursor to your comprehensive GTM, you want to 100% avoid a free tier. The goal of any business is to get users to pay. So you want to understand How Much Will Customers Pay For My Product?
By introducing a free tier, you will corrupt your research. The free tier can come in later as an additional hook to bring in more clients, but I strongly urge you to have strong data independent of the free tier