Autoconf 2.72 was released and is packaged in
devel:tools:building / autoconf
Including it in Tumbleweed was declined as other packages broke in the staging
environment, see https://build.opensuse.org/request/show/1134966

== More details ==
autoconf:testsuite fails to build on i586, other packages are also failing:

libbraille: failed (i586, x86_64)
libreoffice: failed (i586)
resource-agents: failed (i586, x86_64)
tigervnc: failed (i586, x86_64)
wxWidgets-3_2: failed (i586, x86_64)
wxWidgets-3_2:GTK3: failed (i586, x86_64)
wxWidgets-3_2:GTK3-nostl: failed (i586, x86_64)
wxWidgets-3_2:Qt: failed (i586, x86_64)