Here is this week's top 10 ARIA albums:
1. Reverence – Parkway Drive
2. Beerbongs & Bentleys – Post Malone
3. The Greatest Showman (Soundtrack) – Various
4. Graffiti U – Keith Urban
5. ÷ – Ed Sheeran
6. Solastalgia – Missy Higgins
7. KOD – J.Cole
8. Good Thing – Leo Bridges
9. Djarimirri (Child of the Rainbow) – Gurrumul
10. Lost Friends – Middle Kids
I think the Olivia soundtrack can make the top 10 and break the dominance of The Greatest Showman soundtrack, but much will depend on Mother's Day pre-sales and the TV ratings of the mini-series. In 2016, the three-disc soundtrack album to the Channel Seven mini-series Molly reached No.1 on the ARIA albums chart.
I dunno. The Greatest Showman has become a phenomenon unto itself and one I don't think IHLY will be able to put much of a dent in. It has continuously been in the Top 5 on iTunes since its release and a lot of that time at #1. It has been in the ARIA Charts for 5 months now and with the exception of the first week, always in the Top 5.
IHLY is sitting at #8 on iTunes now two days after release. Hopefully, they promote the soundtrack during commercial breaks for Olivia and like you say, the mini-series will hopefully boost sales. The in-stores will hopefully help, too.
A Top 10 debut next week is entirely possible (the lower end I would say), but I definitely wouldn't expect a #1 next week, especially given that Arctic Monkeys released a new album this week too.
I also fear that Seven may have inadvertently shot themselves in the foot with this intense saturation of Olivia promos over the last few months. I've heard a lot of people saying they can't wait for it to air just so they can stop seeing the promos. And given that Delta is a polarising figure amongst Australians, that's definitely not a good thing. But that's more about ratings for the mini-series, not necessarily the album itself.