By 
Welcome pages are pages that come first before the home page of your website. These are used to grab your visitor’s attention and the content may be noticeably different from your website. The main concern is the substance of these pages for the website with respect to the page rank of search engines.
Apart from the fact that many website owners and users find splash pages annoying, they will also have a significant influence on SEO ranking.
Search engines have their own algorithm to compute websites and check what is most relevant to the words typed in the search box. These would rate a site based on the title, content, keywords, and meta tags. These pages, on the other hand, do not own most of this part of a website, which makes your site rank lower.
These pages do not have any content or keyword-rich phrases. These are requirements for ranking, but the lack of a home page would prevent spiders from crawling to the main site and not be able to get the job done.
What these pages have are banners or links that will lead to another page or window, making it difficult to index. This will make the search engine assume that your page has the most important content. This can give the engine useless content on your site, causing them to rank your website unusually low.
You can change, and it is necessary to change it regularly. This is so the engine assumes they are up to date and can index your site.
If you want your site to get a higher page rank, don’t try to create a page for your website. However, if you want to give it a try, do some thorough research on search engine optimized pages.