Topic on Project:Support desk

i noticed my wiki v1.30 didn't seem to contain a "Project" namespace. So i created one, in localsettings.php, using same index nums as mediawiki.org. Manual:Namespace_constants

# PROJECT NAMESPACE
define("NS_PROJECT", 4); 
$wgExtraNamespaces[NS_PROJECT] = "Project";
define("NS_PROJECT_TALK", 5); 
$wgExtraNamespaces[NS_PROJECT_TALK] = "Project_Talk"; 

But, i just discovered:

all wikis have a "Project:" namespace, but the actual namespace name is normally changed to the name of the wiki (on Wikipedia for example, the "Project:" namespace is "Wikipedia:")"  

API:Siteinfo#Namespaces

and i noticed the default localsettings.php contains:

$wgMetaNamespace = 'Project';

• Has my custom "Project" namespace broken anything?
• If i remove my custom namespace declaration, will my pages with "Project:" prefix still load and work correctly? Should i change their prefix to my wiki-name? Currently, if i substitute MyWikiName for Project prefix, i get "page doesn't exist".