That's 100% the case, unfortunately. Anders was never a part of the musical process during the peak years (or probably ever, in any significant way), so you can rule him out straight away. The new members have no history of making MDM, although I respect Tanner's Nightfiends work.
That just leaves Bjorn. We know he contributed to TJR and Whoracle to a degree, but the majority was written by Jesper and Glenn, so the chances of Bjorn on his own being able to authentically replicate that old school MDM sound is slim. Best he could do is something like SoSD where they are copying a band like ATG. I am unsure when it comes to Colony/Clayman sound. Bjorn was a bigger part of the creative process then, so is it possible for him to create something similar now? Maybe. But without Jesper there as a creative partner and guiding hand I don't think it would work.
I do think Bjorn could create something similar to STYE/CC/ASOP if he wanted to, and for sure he could create an album on the same level as SOAPF - as on that one he was, after all, the sole songwriter and it was only 13 years ago. It's clear he doesn't want to put that kind of effort into an album again, or he would have done it by now, but I have no doubt he could if he really wanted to and if Anders would let him. It would mean ditching Benson though, which seems unlikely.
THE is totally different. It's a bunch of guys who are all steeped in the traditions of the genre from the very beginnings - and, more importantly, who appreciate the genre and the audience who still loves that sound. Anders has always had barely hidden disdain for fans of the old material, despite his weak protests of "if yuh don't have dah jestah race you ain't da real fan of in fflames" - yeah, I guess that's why you barely played any songs from that album live for over a decade, bro.
Anyway, in both Jesper and Niclas you have two guys who wrote great MDM during the classic period (even though Niclas' stuff isn't as well known, Gardenian is great work). Daniel had the short-lived but awesome Sacrilege as his own project. Peter showed what he can bring to the table with his contribution to Gateways, and I'm sure he's been helpful elsewhere with composition and ideas. Stanne's credentials need no explanation.
We know Anders and Bjorn don't really appreciate classic MDM. At least, creatively, they don't care for it. Possibly because creating good MDM is beyond their abilities as a duo, so alt metal with MDM influence is the best they can do. If so, fine - better to know your limits and attempt to focus on what you're good at, as opposed to failing at recreating a sound because you're out of your depth, or releasing hollow echoes of a sound that either wasn't yours to begin with or that you've already done and are just mimicking in the hope people won't notice.
Foregone is the only album in the entire IF discography that I totally dropped after a few days and have never come back to it. I could not tell you what the majority of songs on the album sound like, because I don't remember. Even with SC and Battles I listened to them enough to recall what every song sounds like. It would take a lot for IF to totally push me away, but somehow they did it with Foregone. It just felt so fake and plastic to me that I couldn't stand it. I think the reason my reaction to Foregone was worse than Battles, which was also fake and plastic and gross, was that at least with Battles they were being upfront with what they were doing. The California pop-metal thing, they just went balls out with it and said this is us now. We suck but hey, here you go. I don't respect it but at the same time it was just a "lol OK then, get it out of your system lads and let's go again next time". Foregone feels different, more insidious in trying to fool people into believing the band care about "da rootz" and want to be an MDM band again. It's a sham, and to me that's even worse. Battles was laughable, but Foregone is insulting to me.