There are now a series of different flexible delimiters between the parts of a name (when using Biber). They are \bibnamedelima, to \bibnamedelimd plus \bibnamedelimi and the marker command \revsdnamepunct. Their full use cases are described in the manual: basically, \bibnamedelima/\bibnamedelimb go between first names or between surnames (i.e. for gaps within the same 'part' of the name) while \bibnamedelimc/\bibnamedelimd between the first name(s) and surnames (between 'parts'). \bibnamedelimi goes after initials in the first name part, replacing \bibnamedelima/\bibnamedelimb, when conversion to initials is active. Thus depending on the settings, either \bibnamedelimc or \bibnamedelimd applies in the current case (see the manual): it's just a question of altering the definitions
\documentclass{article}\usepackage[backend=biber,natbib=true]{biblatex}\newcommand*{\person}[2]{\citename{#1}[#2]{author}}\DeclareNameFormat{firstinits-last}{% \usebibmacro{name:first-last}{#1}{#4}{#5}{#7}% \usebibmacro{name:andothers}}\DeclareNameAlias{sci}{firstinits-last}\usepackage{filecontents}\begin{filecontents}{\jobname.bib}@misc{latour, AUTHOR = {Latour, Bruno}, OPTIONS = {dataonly=true}}\end{filecontents}\renewcommand*\bibnamedelimc{\addnbspace}\renewcommand*\bibnamedelimd{\addnbspace}\addbibresource{\jobname.bib}\begin{document}Foo bar foo bar foo bar foo bar foo bar foo bar foo bar foo bar foo bar. \person{latour}{sci} says about the ``new object'' that emerges\ldots\end{document}I've altered both setting here, but it's d that applies in the current case.
