I don’t know much about season 1. I started playing during season 2. 
It was of course a thing because of the nature of Ressurect but:
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It literally almost never worked because you’d always get wiped again (still happened after immunity but it made tempo ressing pretty powerful so most Mercy players just ditched the hide strat and opted to stay with their teams)
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It was very rare, only ever done in low ranks, because again, the strategy was inherently bad. If you want a better explanation, just read the Recent Developments section of this thread: