Breakaway, that is not correct , that the weep hole will not weep until warmed up. It should always show a stream. Thermostat does not affect it.
Your right Wiz, I was wrong. Meant to say that it can take a minute or so for enough water to build up in the jacket to pressurize the bypass valve (which occurs before the thermostat opens) and allow water to show at the tell tale. In other words, lack of immediate pissing upon startup isn't neccessarily cause for concern, unless it doesn't start peeing at all. If that happens, look for water coming out the exhaust--so lomg as you have that, your good, engine wise. The tell-tale is just a convenience feature, not the entirety of cooling water being discharged by the engine.