Question

Does this look right? SEO expert said that this is the way to do it, but for some reason I think it could be wrong because we are using the same url for different hreflang

<link rel="alternate" hreflang='en-bn' href='http://www.xxx.com/gsa'/>
<link rel="alternate" hreflang='en-cn' href='http://www.xxx.com/gsa'/>
<link rel="alternate" hreflang='en-hk' href='http://www.xxx.com/gsa'/>
<link rel="alternate" hreflang='en-in' href='http://www.xxx.com/gsa'/>
<link rel="alternate" hreflang='en-id' href='http://www.xxx.com/gsa'/>
<link rel="alternate" hreflang='en-jp' href='http://www.xxx.com/gsa'/>
<link rel="alternate" hreflang='en-kr' href='http://www.xxx.com/gsa'/>
<link rel="alternate" hreflang='en-my' href='http://www.xxx.com/gsa'/>
<link rel="alternate" hreflang='en-pk' href='http://www.xxx.com/gsa'/>
<link rel="alternate" hreflang='en-ph' href='http://www.xxx.com/gsa'/>
<link rel="alternate" hreflang='en-sg' href='http://www.xxx.com/gsa'/>
<link rel="alternate" hreflang='en-lk' href='http://www.xxx.com/gsa'/>
<link rel="alternate" hreflang='en-tw' href='http://www.xxx.com/gsa'/>
<link rel="alternate" hreflang='en-th' href='http://www.xxx.com/gsa'/>

Would Google penalize a website for this?

Answer 1

I think they might. If you see this post on the Google Webmaster Central Blog, they recommend something like the following:

<link rel="alternate" hreflang="es" href="http://www.example.com/" />
<link rel="alternate" hreflang="es-ES" href="http://es-es.example.com/" />
<link rel="alternate" hreflang="es-MX" href="http://es-mx.example.com/" /> 
<link rel="alternate" hreflang="en" href="http://en.example.com/" />

Google says:

If you specify a regional subtag, we’ll assume that you want to target
that region. Keep in mind that all of these annotations are to be used
on a per-URL basis. You should take care to use the specific URL, not
the homepage, for both of these link elements.

---

Also, from their guidelines here,

Have one URL associated with one piece of content. We recommend
against using the same URL for multiple languages, such as serving
both French and English versions on example.com/page.html based on
user information (IP address, Accept-Language HTTP header).
_{(Emphasis mine)}

If you aren’t redirecting the user to different sites based on language/localization, you might get penalized for it, as Google explicitly recommends against it.