Ranked flex tier inflation

I decided when I delved into ranked this season I would only play Ranked Flex as a solo player and ignore solo queue entirely. I made this decision based on two things:

 1). Ranked flex is a much more positive atmosphere with less raging and toxic players
 2). Ranked flex relies more on teamwork and decision making rather than pure mechanical skill, which players try oh so hard to show off in solo queue
       games only to rage and lose (cough cough Yasuo cough cough)

I feel like I made the best decision. However, I'm wondering if rankings in ranked flex are inflated. Perhaps I could hear your opinions on this. I went 6-4 in placements and was placed into Silver IV. Not complaining about my position, I set out to patiently climb (my goal was Gold by the end of the year, nothing too fancy, I had never spent too much time caring about ranked). I sped through that tier and won my first series, and saw myself promoted straight to Silver II. I was gaining +30 LP a win, while only losing 10 per loss, and I was confused at the disparity. Looking at my match history, I noticed I was being matched with Platinum, mid-to-high Gold players, and the occasional Diamond V players, and occasionally I would see Silver players like myself. After a few days, I made it to Gold, supposedly accomplishing my goal less than a month after starting. I decided I would simply keep pushing until I started losing more than winning. After a bit of a grind, I made it to a promo series....only to have myself automatically promoted to Gold III without even playing the series.

After doing some research, I discovered that Riot had implemented a feature back in 2014 that offered a small number of players a Promo series skip if they were playing with high-ranking players and winning. It wouldn't surprise me that this is still in place. However, when we look at the big picture, is the same thing happening in Solo queue? Why am I getting matched with such high-ranking players? I'm still earning +30 LP a win, I'm climbing quicker than I thought, and I'm playing really well against these players, but somehow it feels a little watered-down. I know the rewards for Ranked Flex will likely be the same for Solo queue, so I'm not bummed. I'm just curious to hear someone else's perspective on this.