I am replacing the battery "right now" on a MBA 2019 True Tone & noticed the replacement battery does NOT have any of the adhesive strips mentioned. I plan to test a couple of solutions on reassembly ONLY IF NEEDED. 1st, I'll apply several strips of the 2 sided tape, (known as "Adhesive Strip kit used to secure display on iMac). NOTE: Tesa 61395 Tape available on the ifixit.com website;
Tesa 61395 Tape / "Good Stuff"! Some of the best available at any price!
Throughout the reassembly process closely watching for any battery movement to confirm. In the event battery slide / slipping is discovered, disassemble & place "Thermal Pad" custom cut into the 3 grooves on each side. Apply display strip tape onto the pads - reassemble. In the event keeping the battery safely in place; disassemble - remove all pads & tape. Clean & apply "Thermal Conductive Plaster". Silicone Viscous Adhesive Compound designed for just such a need. If Thermal Conductive Plaster is required I pity the individual that attempts to replace the battery in the future. I would also write a "warning" "permanent marker" inside (bottom case) alerting anyone's future efforts. At the very least providing information what to expect hopefully preventing serious damage. Many tech's reading such a warning would stop the repair and investigate.
It would require an extreme amount of movement before EVER CONSIDERING Thermal Conductive Plaster as a solution to ANYTHING that could POSSIBLY require a future repair.
NOTE: IMHO - Anyone working on digital equipment should make the above mentioned a part of your tool bag. Especially - Thermal Pads - 0.5mm, 1.0mm & 2.0mm, "thicknesses at the very least". If working on iMac(s) 2 sided display tape in roll rather than " custom cut" is considerably less costly. I actually find it easier to work with if you purchase a decent product. Thermal Glue is another essential but beware there is good and down right "miserable" products to be had. Thermal Conductive Plaster is a bit spend y & should only be considered when NO FUTURE DISASSEMBLY is the plan. A much better solution would be E6000 Adhesive Glue available from IFIXIT - E6000 Adhesive Glue A phenomenal silicone glue that "could be" separated if needed in the future -- "MAYBE". I absolutely LOVE E6000. E6000 has been a go to for many years & earned my respect! Over the years have learned many adhesive lessons the hard way...
I hope this helps,
Douglas Swinhart ~~ Semi-retired (4+ decades self-employed System Administrator / Configuration Specialist)