Follow-up Email to Interviewer?

I applied to a junior research analyst role at a BB (non-campus program but it opens to fresh graduate w/o full-time work experience). My first interview was a sceening call with HR and then I talked to a Co-Head of the department (MD level) in my second interview. Around one week later, I also talked to a senior analyst at ED level and another Co-Head of the department (MD level), respectively. 

I haven't heard from them for around one and a half week since my last interviews, and the last time when I checked with HR (two days ago), she told me she is still waiting on everyone’s feedback but when she does she’ll reflect in the system and said: “Kindly please keep checking your status in the system regularly.”

Does it sound like a rejection or should I keep waiting for an update? Is it okay to send a follow-up email to the interviewers? (It was always HR that was in touch with me so I am supposed not to know the emails of the interviewers, i.e. the Co-Head and senior analyst)

I am thinking about writing a thank-you email to them all the while implying that I want a follow-up. My email subject would be “Thank you,” and start with a line saying something like “I apologize for the abrupt nature of this email, but I have taken the liberty to write to you...after coming across your email address from one of your older research reports.” And then recall parts of the interview with him/her, reiternate my interest in the position, and say I look forward to hearing back from them ,etc. 

Does it sound like a good idea or is it trying too hard and may seem a bit awkward to contact the interviewers directly via their work email (or even through a LinkedIn in-mail)?