Question about Temporary Domain Forward

Hi everyone,

I have a quick question. I currently have an operational Shopify store. The URL is a subdomain of my blog, which I'm still building and haven't launched yet. I am doing some social media marketing to the Shopify URL, however I've noticed some people are commenting that they're going to the blog domain instead of the advertised Shopify subdomain and they're just seeing a coming soon page.

My question is: would there be any potential downsides if I do a temporary domain forward from the blog to the Shopify subdomain while I get ready to launch the blog? The blog doesn't have much content at this point. I just want to make sure I don't do anything that would mess up future indexing or SEO.

Thank you