Response to manager sorry-not-sorry email

[WhoCanThinkOfaChangeofName]

Scenario:
Me, my former line manager (FML) and my new line manager (NML, I'm 9 months in new role with the two workstreams intertwined) meet to discuss workstream progression, third of a series of meetings. FML continued as previous meetings - talking over me and NML, shouting over us as we tried to continue to speak, clear allusions to holding the funds for my role (turns out he doesn't I learned today).
Context:
Following last such meetings NML wanted to report FML's attitude, tone and manner towards me - bullying, belittling and dismissive. I didn't want any trouble in a new role, despite this being from NML clearly on my side so said no.
What followed
NML went to the boss of both her and him, and spoke to FML on peer level to call him out. Ultimate Boss spoke to me, called FML who immediately said he had something to tell her and owned it all.
But!
In between he sent a sorry-not-sorry email to me that actually contained the words 'I'm sorry I made you feel that way'.
So
I don't want to be seen as a troublemaker, but I'm buggered if I'll acquiesce; your suggestions please strong hive mind -
1.ignore
2.thank you for your email, the contents have been noted
3.Thanks X, let's move on

Has the managers boss accepted the apology/put it to one side as being dealt with?

Did they ask what outcome you were looking for? Have they offered any resolution beyond the brush it under the carpet non apology email?

I wouldn't say anything at present and see how the next couple of weeks pan out, then review. What a horrible situation. I'm so sorry.

Thank you for your help.
Ultimate Boss promised to speak to him Friday afternoon, which she did, and to update me, which she didn't/ hasn't.
NML updated with the 'he owned it all as soon as she called'. No update from Ultimate Boss but instead an ask from UM at 5.15 today for input on a new project I've been asked to lead on a strategic insight and development project with potentially massive local and national impact, for inclusion in an important stategic paper she's writing this week.
UM has never been so directly personal or asked for this type of report before, but not reading too mucn into this as the new project is part of my new role.

In between he sent a sorry-not-sorry email to me that actually contained the words 'I'm sorry I made you feel that way'

That's an apology. He took responsibility, "I made" - his actions. It would have been a sorry-not-sorry email if he'd written "I'm sorry you feel that way".

What also matters though is what was in the rest of the email; did he refer to the meeting of X, which anchors what he said to the specific event.

Sorry, I should have quoted him verbatim for context. What he wrote was:
I wanted to follow up after yesterday's meeting. I’m very sorry it left you feeling upset, that was certainly not my intention. My aim wasn’t to assign blame or highlight individual failings, but to reset and refocus so the work is delivering against the needs of the programme.
This was in reference to a small part of my work with an external stakeholder where progress had to pause due to their whole programme shake-up that affected funding and staffing. The first words out of his mouth in the meeting were 'why has there been no progress with X?' despite having been told in the previous meetings that a pause was going to occur and it having been stated in my monthly and quarterly reports.

Don't reply. An email like that doesn't actually need one, and you don't want to do anything that either implies you have accepted the apology and the matter is entirely resolved or that could be interpreted as escalating/inflaming the situation.

Thank you, that's the conclusion I'd reached.
Thanks everyone, I really appreciate your help with this.