The worst horrors which any web developer might have is to look out for all the SEO juice acquired through and continually lost during the migration process. According to the latest existing trends, your renewed website won’t be considered as changed but a totally fresh one. So neither Google or any other search engine cannot rank you at this point.
But that can happen if you don’t remember that SEO issue while renewing your website. Surely, none can provide an accurate prediction of what the world’s reaction would be to your choice. There are some ways through which you can avoid such a downfall.
First and foremost, consider adding a number of useful options such as Redirect and Meta Data Migration to your migration list. To migrate without pre-migration checklist, staging environment needs to be blocked from being crawled by search engines utilizing HTTP authentication. The CMS2CMS infographic has a detailed checklist for SEO migration.