No.
Your MMR of the previous season will be taken into account when you play your placement matches of the following season. If you are Gold V you will be likely placed at the same ranking if you play average for your level.
This ofcourse means if you do better than average, you will be likely placed higher than Gold V and vice versa if you play worse than average.
The 1200 ELO formula only counts for Summoners who have never played ranked games before. (Source: http://leagueoflegends.wikia.com/wiki/Elo_rating_system)
Soft ranking reset indeed means you get to play your 10 placement matches again to get you placed at your level.