Migrating from WordPress to OJS for pubblication and indexing problems

For the past year, I have managed an academic journal website. Earlier this year we started using OJS for submission management, while publishing is via WordPress (and a plugin written specifically by the previous webmaster). But since the code is starting to get old, I would like to propose to the board to use OJS for publishing as well.
One problem with a possible migration concerns the indexing of already published articles.
If I replace the WordPress site with OJS, on which I will re-upload the articles, I might have problems for a few months on Google Scholar, since the previous links would be offline and the new ones on OJS would have to index.
Do you have any advice regarding how to best approach this migration?

Best regards,