my guess is that motown was caught a bit off guard with Walking. it too SO long to do anything. and in the meantime Love Hangover was everywhere. I know some fans have stated on here that Scherrie told them while visiting some djs and radio stations, they supposedly literally heard from another motown exec to pull Walking and push Hangover. i don't know the validity or details around but the dates clearly show the timeline.

Walking and Hangover were both released as 45s on the exact same day. talk about poor timing! lol while LH was a mega hit, it was mostly off the dance charts by the time Walking really started to take off. I don't know why or how Walking didn't simply get lost in the shuffle. certainly other great songs before it did. but somehow it hung on there. and based on the NYC store data and the various regional disco charts, Walking was a smash. I haven't gone through the chart data on LH as in-depth but will probably do that. good to compare

Tons of big disco hits did NOT cross over. this was over a year prior to Sat Night Fever and while disco was becoming more mainstream, it wasn't taking over Top 40 like it would later.

I do agree that it appears that the Hollands jumped on the opportunity to do something more/bigger/better with new music rather than continue to explore the hit potentials on the HE lp. lots of fans like You're What's Missing or Teardrops. Even HE and Only You were solid tunes. but none really have the sound or spark like Walking. so IMO the Hollands decided to jump on the chance for new tunes

as for why then the bubble was burst - my guess is 1) the intergroup problems and fighting and 2) motown wanted to manage the group.

with 0 promotion, Walking did quite well and the HE lp sold very respectably. there was now a sound and approach that had been proven to work. motown probably said we want to manage this situation, get that ignorant Pedro out of here and lets get the group back to some level of profitability. when mary and pedro didn't go for the motown management, motown probably said "ok and fuck you too"