Deleting and re-uploading products after Shopify theme redevelopment

I am looking for advice on the best practice for removing a Shopify store’s current database of products and re-uploading a new product list to the database. I’m hoping this will calm my nerves and ensure I am following the best way to achieve my desired result.

So I have 50,000+ products that I uploaded to my development site. I have then gone on to build the website including the product pages, collections and all the bells and whistles.

Now all the features are added, I have been given a new product database to upload, where some products have been dropped, a lot have been updated and a lot have been given new tags or product types.

As it is such a large change to the product list I would ideally be able to delete the existing database, then upload the new product database (as they are so different). I have also made changes myself to a lot of the products to test discounts and other general testing purposes, so these changes would be rectified without my involvement and will match the new product export I have been given.

So all this in mind, am I able to delete the whole range of products loaded in, re-upload the new list, while maintaining the existing collections and tag filters?

I appreciate this is not a question I can provide code examples of, more a resource for best steps to completely refresh a product database while maintaining existing collection and tagging.