I have to study a strategy for a page where the contents are updated about once a month and the title and the url are always the same. As now, in the page there's only a video. To improve the seo for that page I thought to suggest my customer to add a transcription of the video to improve rankings. I read that in case of video < ~ 15 minutes it is suggested to add a textual transcription to make available the keywords that are used in the video.
I have some doubts, because this page will have always the same url/title while the text and the video will change monthly. Suppose that the page will be positioned on the serp for a given keyword present in the transcription, in the next month the topic may change and then there could be no more keywords regarding that topic. Being the url/title always the same, will this penalise the seo?
I mean, I don't know if the results are cached and then even if it seems that the page contains a given keyword there is the chance that the user see the new contents where that keyword is no more present.
In this case, is it better to suggest to change the url/title too? Consider that the old content cannot be available on the site anymore, so the page will be always that one. My doubt is if it is better to change the url/title (let's say as it was a new page) or to maintain the old url/title static (in this case i don't know if changing the text and video will penalise it).