revise message again

Author: p

lib/mongoid/fields/validators/macro.rb

@@ -116,7 +116,7 @@ def validate_options(klass, name, options)
             if option == :type && options[option] == Symbol
               @field_type_is_symbol_warned ||= begin
                 Mongoid::Deprecation.warn(<<~MSG.squish.freeze)
-                  The BSON Symbol type is deprecated. Please use String or StringifiedSymbol instead
+                  The BSON Symbol type is deprecated by MongoDB. Please use String or StringifiedSymbol field types instead of the Symbol field type
                 MSG
                 true
               end